diff --git a/.agents/skills/local-database/SKILL.md b/.agents/skills/local-database/SKILL.md
index 763491b8..d0d5971c 100644
--- a/.agents/skills/local-database/SKILL.md
+++ b/.agents/skills/local-database/SKILL.md
@@ -22,6 +22,18 @@ VMs Cloud **não rodam** `docker compose` / `pnpm db:start`. Postgres nativo: `.
 - Dev database: `postgresql://teqo:teqo@localhost:5432/teqo`
 - Test database: `postgresql://teqo:teqo@localhost:5432/teqo_test`
 - Local Postgres major version is pinned to **17** in `docker-compose.yml` to match production Neon.
+- **In a worktree provisioned by `pnpm worktree next`**, read `.env.local` / `.env.test.local` instead: dev database `teqo_wt<slot>`, test database `teqo_wt<slot>_test`, dev server on port `3100+slot` (see "Per-worktree environments" below).
+
+## Per-worktree environments (`pnpm worktree next`)
+
+Parallel agents must not fight over port 3000, the shared `teqo_test`, or a second Postgres container. `pnpm worktree next [--go]` provisions each worktree with a deterministic isolated env:
+
+- `slot` = numeric part of the issue code (`C15` → 15, `B164` → 164; hash fallback without digits; bumped on collision among live worktrees).
+- Dev server port `3100+slot`; databases `teqo_wt<slot>` (dev) and `teqo_wt<slot>_test` (tests), created on the **one shared container** with the full migration chain applied (one-time, ~30 s each).
+- Writes `.env.local` (DATABASE_URL, PORT, NEXT_PUBLIC_SITE_URL, PLAYWRIGHT_BASE_URL, PAYLOAD_SECRET + Blob/VAPID copied from the main repo) and `.env.test.local` (test DATABASE_URL). Both carry the marker `# teqo worktree env (generated by pnpm worktree next)`; **manual env files are never overwritten** — remove them and re-run `pnpm worktree next` to regenerate.
+- `--no-migrate` skips the migration runs; `pnpm worktree kill` drops the worktree's generated databases (best-effort, `DROP DATABASE … WITH (FORCE)`).
+- Without Docker (Cursor Cloud) it degrades to the shared `teqo`/`teqo_test` with a warning and no port override.
+- Pure derivation: `scripts/lib/worktree-env.mjs` (unit-tested in `tests/unit/worktree.unit.spec.ts`).
 
 ## First-time setup
 
diff --git a/.agents/skills/worktree-next-issue/SKILL.md b/.agents/skills/worktree-next-issue/SKILL.md
index e474b685..cff6bda2 100644
--- a/.agents/skills/worktree-next-issue/SKILL.md
+++ b/.agents/skills/worktree-next-issue/SKILL.md
@@ -19,8 +19,8 @@ Prepara o ambiente git para a próxima Issue da fila de claim, **sem** tocá-la
 A lógica determinística (fila → código+slug → branch → worktree) vive em **`scripts/worktree.mjs`** — fonte única, coberta por `tests/unit/worktree.unit.spec.ts`. Não a reescreva à mão aqui.
 
 ```bash
-pnpm worktree next            # cria worktree de origin/main para a próxima claimável
-pnpm worktree kill [--force]  # destrói o worktree em que o shell atual está
+pnpm worktree next [--go] [--no-migrate]  # cria worktree de origin/main + provisiona o ambiente
+pnpm worktree kill [--force]              # destrói o worktree atual + remove seus bancos gerados
 ```
 
 No opencode, isso é o comando **`/worktree next`** / **`/worktree kill`** (`.opencode/commands/worktree.md`), que só repassa `$ARGUMENTS` para o script.
@@ -38,9 +38,20 @@ No terminal interativo, para `--go` trocar de diretório de verdade, use a funç
 - **Fila = `pnpm agent:claim --dry-run`** (ready + desbloqueadas, por `prio:P*` e mais antiga primeiro — mesma ordenação do pool e de `project-status`).
 - **Branch `<code>-<slug>`**: `code` = `id` do frontmatter; `slug` = título pt-BR via `src/lib/slug.ts` (acentos fora, não-alfanumérico → hífen); truncamento só no slug, nunca no código; valida com `git check-ref-format --allow-onelevel`.
 - **Base `origin/main`** (com `git fetch` antes); dir em `~/.cursor/worktrees/teqo/<branch>`.
-- **`kill`**: recusa destruir o worktree principal (main); recusa worktree sujo sem `--force`; remove e apaga o branch.
+- **Provisiona o ambiente isolado do worktree** (determinístico, ver "Ambiente provisionado"): dev server na porta `3100+slot` e bancos próprios `teqo_wt<slot>` / `teqo_wt<slot>_test` no container compartilhado (`-p teqo`), com migrations aplicadas — agentes em paralelo não disputam porta 3000 nem o `teqo_test`. `--no-migrate` pula as migrations (bancos criados, envs escritos).
+- **`kill`**: recusa destruir o worktree principal (main); recusa worktree sujo sem `--force`; remove e apaga o branch; remove os bancos gerados do worktree (best-effort).
 - **NUNCA usa `--force` no `add`**, não inventa código de Issue, e é **read-only no GitHub**.
 
+## Ambiente provisionado (leia a saída do script)
+
+Cada worktree gerado ganha um ambiente próprio — reporte ao agente/humano os valores que o script imprime ao final:
+
+- **dev**: `http://localhost:<porta>` (`pnpm dev`), banco `teqo_wt<slot>`.
+- **test**: banco `teqo_wt<slot>_test` (as suites leem `.env.test.local`, que sobrepõe o `.env.test` commitado; `pnpm test:int` / `test:e2e` / `gate:push` rodam isolados).
+- Sem Docker (Cursor Cloud): o script degrada para o compartilhado `teqo`/`teqo_test` com aviso — comportamento antigo.
+- Envs geradas têm o marcador `# teqo worktree env (generated by pnpm worktree next)`; **`.env.local`/`.env.test.local` manuais nunca são sobrescritos** (o script pula o provisionamento com aviso).
+- Detalhes e derivarão pura: `scripts/lib/worktree-env.mjs`; skill `local-database`.
+
 ## NÃO faz
 
 - Não roda `pnpm agent:claim` (mudaria labels no GitHub).
diff --git a/AGENTS.md b/AGENTS.md
index 7f4f769a..06418c46 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -33,7 +33,8 @@ These are product/architecture constraints — not a ban on editing existing cod
 - Schema changes go through committed Payload migrations — `push: false` everywhere, never flip it on against a remote DB. Edit configs → `pnpm migrate:create <name>` → commit `src/migrations/*` (both `.ts` and `.json`, plus `index.ts`) → `pnpm migrate` locally. `pnpm build` runs `payload migrate`, so **every Vercel deploy applies pending migrations to prod**. Prod is baselined at migration `20260715_163458_initial` — never regenerate or replace the initial migration. Full workflow (incl. hand-written data/reconciliation migrations) lives in the `payload-migrations` skill (`.agents/skills/payload-migrations`).
 - `Consent.text` was reconciled from `varchar` to `jsonb` via `20260715_163500_consent_text_to_jsonb` (matching the `richText` field). Any future field-type change is a migration, not a manual DB edit.
 - To copy production content locally, use `pnpm db:pull` (`scripts/db-pull.mjs`): it only reads prod, only writes local, and excludes supporter PII (`contact`/`signature`/`subscription` row data).
-- `pnpm db:doctor` diagnoses local database connectivity for the dev AND test targets: it names who holds the port, points at exited/crash-looping containers, and flags Postgres containers sharing one data volume (two postmasters on one PGDATA corrupt the WAL — this destroyed the local cluster's checkpoint on 2026-07-25; the canonical setup is ONE compose container on 5432 hosting `teqo` + `teqo_test`). `pnpm dev` runs the same preflight via `guard-dev-db` and refuses to start with a named remedy instead of a later ECONNREFUSED.
+- `pnpm db:doctor` diagnoses local database connectivity for the dev AND test targets: it names who holds the port, points at exited/crash-looping containers, and flags Postgres containers sharing one data volume (two postmasters on one PGDATA corrupt the WAL — this destroyed the local cluster's checkpoint on 2026-07-25; the canonical setup is ONE compose container on 5432 hosting `teqo` + `teqo_test`). `pnpm dev` runs the same preflight via `guard-dev-db` and refuses to start with a named remedy instead of a later ECONNREFUSED. `db:start`/`db:stop` pin the compose project with `-p teqo`, so they always target that ONE container even from a worktree directory.
+- **Per-worktree environments (`pnpm worktree next`, 2026-08-08):** parallel agents each get a deterministic isolated env — no fighting over port 3000, the shared `teqo_test`, or a second Postgres container. `worktree next [--go]` provisions: a dev-server port `3100+slot` (slot = numeric part of the issue code, hash fallback, bumped on collision among live worktrees), plus dedicated databases `teqo_wt<slot>` (dev) and `teqo_wt<slot>_test` (tests) created on the shared container with the full migration chain applied; writes `.env.local` + `.env.test.local` (gitignored, marker `# teqo worktree env (generated by pnpm worktree next)`; manual envs are never overwritten) and copies `PAYLOAD_SECRET`/Blob/VAPID from the main repo. `kill` drops the worktree's generated databases best-effort. Tests read `.env.test.local` after `.env.test` (vitest.setup.ts / playwright.config.ts / db-doctor / gate-ci mirror the layering), and `assertTestDatabase` accepts `teqo_test` or `teqo_<worktree>_test` on localhost only — still fail-closed on remote. Pure derivation lives in `scripts/lib/worktree-env.mjs` (unit-tested). Without Docker (Cursor Cloud) it degrades to the shared `teqo`/`teqo_test` with a warning.
 - To (re)populate news content, `pnpm db:seed:posts` fetches articles live from jorgesolla.com.br into the LOCAL db (same non-local `DATABASE_URL` guard as `pnpm dev`). It writes from a CLI process outside the deployed runtime, so after seeding — or after ANY direct-DB change — you must bust the production `posts` cache via `POST /api/revalidate`. See "Posts & Tags" below.
 - To (re)populate the TSE 2022 election baseline, `pnpm db:seed:tse` downloads TSE open data and imports the Bahia scope into the LOCAL db (same guard). Since the 2026-07-23 hardening, elections-tab reads are cached under the `election-tse` tag — after re-seeding a database the deployed app reads, bust it via `POST /api/revalidate?tag=election-tse`. See "Election baseline data (TSE 2022)" below.
 
@@ -154,7 +155,7 @@ The artifact is at **v3**: v2 added E8's `campoFederalVotesByYear` / `federalTal
 
 ### Local verification and deploy checklist
 
-1. Confirm `DATABASE_URL` is `postgresql://teqo:teqo@localhost:5432/teqo` and `.env.test` points to `teqo_test`; never use Neon for development, tests, E2E, or local builds.
+1. Confirm `DATABASE_URL` is `postgresql://teqo:teqo@localhost:5432/teqo` and `.env.test` points to `teqo_test`; never use Neon for development, tests, E2E, or local builds. In a provisioned worktree (`pnpm worktree next`) the values come from its `.env.local` / `.env.test.local` (`teqo_wt<slot>` / `teqo_wt<slot>_test`, dev port `3100+slot`) — read them there instead of assuming the main-repo names.
 2. Run `pnpm db:start`, `pnpm migrate:status`, and `DATABASE_URL=postgresql://teqo:teqo@localhost:5432/teqo_test pnpm migrate:status`; every migration must show `Ran: Yes`.
 3. Run `pnpm generate:types`, `pnpm generate:importmap` when components changed, `pnpm exec tsc --noEmit`, `pnpm lint` (zero warnings — the script enforces `--max-warnings=0`), `pnpm format:check` (Prettier is the formatting authority; `pnpm format` fixes), `pnpm exec knip` (dead files/dependencies are CI-blocking; delete what your change orphaned), `pnpm check:cycles` (madge — zero circular imports), `pnpm test` (unit + int), `pnpm test:e2e` (or `pnpm test:all`), and `pnpm build` against the local database. Payload CLI scripts (`migrate`, `generate:*`, `payload`) and the build migrate step use `--conditions=react-server` so `server-only` modules load correctly outside Next.js.
    - Never run `knip --fix` blind: when knip's module graph is incomplete (it still cannot load `payload.config.ts` — ledgered as P3), `--fix` deletes exports that migrations/tests still reference. Verify each removal (e.g. `git grep -w <symbol>`) before deleting.
diff --git a/README.md b/README.md
index 894a667f..6186fb6c 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,9 @@ Teqo then becomes a configurable base product for other politicians in Brazil:
 6. Start the dev server: `pnpm dev`
 7. Open: `http://localhost:3000`
 
-Useful scripts: `pnpm db:start` / `pnpm db:stop` (local Postgres), `pnpm db:pull` (refresh local content from prod), `pnpm db:seed:posts` (import news posts/tags fresh from the live jorgesolla.com.br site into the local db; idempotent by slug, refuses a non-local database), `pnpm db:seed:tse` (import TSE 2014/2018/2022 Bahia election results into the local db; idempotent per year/office/turn scope, refuses a non-local database), `pnpm build:election-aggregates` (regenerate the committed TSE aggregate artifact in `src/lib/electionAggregates/` from locally seeded data).
+Useful scripts: `pnpm db:start` / `pnpm db:stop` (local Postgres — always the same shared container via `-p teqo`, from any directory), `pnpm db:pull` (refresh local content from prod), `pnpm db:seed:posts` (import news posts/tags fresh from the live jorgesolla.com.br site into the local db; idempotent by slug, refuses a non-local database), `pnpm db:seed:tse` (import TSE 2014/2018/2022 Bahia election results into the local db; idempotent per year/office/turn scope, refuses a non-local database), `pnpm build:election-aggregates` (regenerate the committed TSE aggregate artifact in `src/lib/electionAggregates/` from locally seeded data).
+
+Parallel worktrees get isolated environments: `pnpm worktree next` derives a per-branch dev port (`3100+slot`) and its own databases (`teqo_wt<slot>` / `teqo_wt<slot>_test`), so agents never fight over port 3000 or the shared `teqo_test`. See `.agents/skills/local-database`.
 
 ### Content & cache revalidation
 
diff --git a/docker-compose.yml b/docker-compose.yml
index b469ebb2..a83ef4fa 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,8 +15,11 @@ services:
       - '5432:5432'
     # Default max_connections=100 is tight for vitest forks (≈CPUs × pg pool)
     # plus a leftover `next start` from local repro. Raise the ceiling so the
-    # int gate fails on real assertions, not "too many clients already".
-    command: ['postgres', '-c', 'max_connections=200']
+    # int gate fails on real assertions, not "too many clients already". 400
+    # leaves headroom for several agents' int suites on the SAME container in
+    # parallel (each worktree provisions its own databases — see
+    # scripts/worktree.mjs — but they share this one Postgres on 5432).
+    command: ['postgres', '-c', 'max_connections=400']
     volumes:
       - pgdata:/var/lib/postgresql/data
       # Runs only on first initialization of the volume. Creates the dedicated
diff --git a/docs/CHANGELOG-AGENTS.md b/docs/CHANGELOG-AGENTS.md
index 139bb9cf..fdf86331 100644
--- a/docs/CHANGELOG-AGENTS.md
+++ b/docs/CHANGELOG-AGENTS.md
@@ -4,6 +4,8 @@ Conteúdo movido do `AGENTS.md` em 2026-07-30 (fatiamento do paradigma de agente
 
 ---
 
+**Recently resolved (2026-08-08):** **worktree next provisiona ambiente isolado por worktree** — agentes em paralelo não disputam mais porta 3000, o `teqo_test` compartilhado nem um segundo Postgres no 5432: `pnpm worktree next [--go] [--no-migrate]` deriva deterministicamente slot do código da Issue (C15→15; hash sem dígitos; bump em colisão entre worktrees vivos) → dev server `3100+slot`, bancos `teqo_wt<slot>`/`teqo_wt<slot>_test` criados no container compartilhado com migrations aplicadas; escreve `.env.local` + `.env.test.local` (gitignored, marcador gerado; envs manuais nunca sobrescritos) e copia PAYLOAD*SECRET/Blob/VAPID do main. `kill` dropa os bancos gerados (best-effort, WITH FORCE). Suites leem `.env.test.local` depois de `.env.test` (vitest.setup/playwright/db-doctor/gate-ci espelham o layering); `assertTestDatabase` aceita `teqo_test` ou `teqo*<worktree>\_test`em localhost só (fail-closed preservado).`db:start`/`db:stop`fixam`-p teqo`(um container, qualquer diretório); max_connections 200→400. Sem Docker (Cursor Cloud): degrada ao compartilhado com aviso. Derivação pura`scripts/lib/worktree-env.mjs` (unit-tested).
+
 **Recently resolved (2026-08-07):** **C15** (Issue #390) — `/campanha/agenda` virou a entrada operacional staff com FullCalendar v7 route-local (semana/mês/lista), filtros compartilháveis por município/deputado/tag, criação pelo slot, detalhe por URL e remarcação drag/resize sob RBAC, transação e lock por atividade; `/campanha/atividades` e giros permanecem como lista/fluxos legados. Sem migration. Impl [`fullcalendar-agenda-campanha-impl.md`](plans/fullcalendar-agenda-campanha-impl.md).
 
 **Recently resolved (2026-08-06):** **B163** (Issue #391) — `/campanha/dobradinhas` agora edita Nome, Partido, E-mail e Telefone inline; `Contact` virou a fonte de identidade, dobradinha nova cria o Contact na mesma transação, e a ficha usa ID canônico com fallback/redirect de slugs antigos. A migration faz backfill idempotente, preserva nomes legados com preflight de limite, mantém a invariável de nome/telefone e o importador da projeção também reencontra dobradinhas pelo nome atual do Contact quando o alias legado diverge; os links de relações/busca apontam para ID. Intenção [`editar-campos-lista-dobradinhas.md`](plans/editar-campos-lista-dobradinhas.md); impl [`editar-campos-lista-dobradinhas-impl.md`](plans/editar-campos-lista-dobradinhas-impl.md).
diff --git a/package.json b/package.json
index cb075434..5eb1917f 100644
--- a/package.json
+++ b/package.json
@@ -22,8 +22,8 @@
   "type": "module",
   "scripts": {
     "build": "cross-env NODE_OPTIONS=\"--no-deprecation --conditions=react-server\" payload migrate && cross-env NODE_OPTIONS=\"--no-deprecation --max-old-space-size=8000\" next build",
-    "db:start": "docker compose up -d postgres",
-    "db:stop": "docker compose down",
+    "db:start": "docker compose -p teqo up -d --wait postgres",
+    "db:stop": "docker compose -p teqo down",
     "db:doctor": "node scripts/db-doctor.mjs",
     "db:pull": "node scripts/db-pull.mjs",
     "db:seed:posts": "cross-env NODE_OPTIONS=\"--no-deprecation --import=tsx/esm --import=./scripts/seed-loader.mjs\" node scripts/seed-posts.mjs",
diff --git a/playwright.config.ts b/playwright.config.ts
index 91fe8301..1b17c023 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -9,6 +9,9 @@ import { assertTestDatabase } from './tests/helpers/assertTestDatabase'
  * `override: true` guarantees the test DB wins over anything in the shell.
  */
 loadEnv({ path: '.env.test', override: true })
+// Per-worktree isolation: `.env.test.local` (gitignored, written by
+// `pnpm worktree next`) wins over the committed `.env.test` when present.
+loadEnv({ path: '.env.test.local', override: true })
 
 // Optional local override when the default Docker port is occupied (e.g. mapped
 // to 5433) — same escape hatch vitest.setup.ts documents.
diff --git a/scripts/db-doctor.mjs b/scripts/db-doctor.mjs
index 1ccd7b3e..6d582d11 100644
--- a/scripts/db-doctor.mjs
+++ b/scripts/db-doctor.mjs
@@ -243,13 +243,24 @@ const readEnvFile = (path) => {
   }
 }
 
+/**
+ * Test target exactly as the suites resolve it: `.env.test` then
+ * `.env.test.local` (per-worktree, gitignored, wins), then the
+ * TEQO_TEST_DATABASE_URL escape hatch beats DATABASE_URL (same order as
+ * vitest.setup.ts / playwright.config.ts).
+ */
+const readTestTargetEnv = () => {
+  const layered = { ...readEnvFile('.env.test'), ...readEnvFile('.env.test.local') }
+  return layered.TEQO_TEST_DATABASE_URL ?? layered.DATABASE_URL
+}
+
 const main = async () => {
   // Next.js precedence for the dev target, without mutating process.env.
   const devUrl =
     process.env.DATABASE_URL ??
     readEnvFile('.env.local').DATABASE_URL ??
     readEnvFile('.env').DATABASE_URL
-  const testUrl = readEnvFile('.env.test').DATABASE_URL
+  const testUrl = readTestTargetEnv()
 
   let healthy = warnOnSharedDataVolumes()
   if (devUrl) {
diff --git a/scripts/gate-ci.mjs b/scripts/gate-ci.mjs
index f670d8cd..356d3cd5 100644
--- a/scripts/gate-ci.mjs
+++ b/scripts/gate-ci.mjs
@@ -19,11 +19,17 @@ import { diagnoseDatabaseTarget } from './db-doctor.mjs'
 const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..')
 
 const readTestEnv = () => {
-  try {
-    return parseEnv(readFileSync(path.join(repoRoot, '.env.test'), 'utf8'))
-  } catch {
-    return {}
+  // `.env.test.local` (per-worktree, gitignored, written by `pnpm worktree next`)
+  // wins over the committed `.env.test`, mirroring vitest.setup.ts.
+  const layered = {}
+  for (const name of ['.env.test', '.env.test.local']) {
+    try {
+      Object.assign(layered, parseEnv(readFileSync(path.join(repoRoot, name), 'utf8')))
+    } catch {
+      // file missing — fine
+    }
   }
+  return layered
 }
 
 const testEnv = readTestEnv()
@@ -31,7 +37,10 @@ const testEnv = readTestEnv()
 /** Env for migrate / seed / build — matches ci-pr.yml service Postgres. */
 const dbEnv = {
   ...process.env,
-  DATABASE_URL: testEnv.DATABASE_URL ?? 'postgresql://teqo:teqo@localhost:5432/teqo_test',
+  DATABASE_URL:
+    testEnv.TEQO_TEST_DATABASE_URL ??
+    testEnv.DATABASE_URL ??
+    'postgresql://teqo:teqo@localhost:5432/teqo_test',
   PAYLOAD_SECRET: testEnv.PAYLOAD_SECRET ?? 'test-only-secret-not-used-in-production',
   NEXT_PUBLIC_SITE_URL: testEnv.NEXT_PUBLIC_SITE_URL ?? 'http://localhost:3000',
 }
diff --git a/scripts/lib/worktree-env.mjs b/scripts/lib/worktree-env.mjs
new file mode 100644
index 00000000..9a3b3bf6
--- /dev/null
+++ b/scripts/lib/worktree-env.mjs
@@ -0,0 +1,67 @@
+/**
+ * Pure helpers for the per-worktree environment provisioning in
+ * `scripts/worktree.mjs` — deterministic port + database names derived from
+ * the branch, so parallel agents (each in their own worktree) never fight
+ * over port 3000, the shared `teqo_test` database, or a second Postgres
+ * container on 5432.
+ *
+ * Contract: `slot` is the single collision domain. Port and BOTH database
+ * names derive from the final slot, so a bumped slot frees all three at
+ * once. Deterministic for a given (branch, code, live taken-slots set) —
+ * the same "depends on live state" determinism the claim-queue branch picker
+ * already has.
+ */
+
+/** Dev-server ports start here: slot 15 → http://localhost:3115. */
+export const DEV_PORT_BASE = 3100
+
+/** Marker line identifying a generated env file (never overwrite manual ones). */
+export const GENERATED_ENV_MARKER = '# teqo worktree env (generated by pnpm worktree next)'
+
+/** Slot cap — ports above 3100 + 999 would leave the usual ephemeral range. */
+const MAX_SLOT = 999
+
+/** First run of digits in the issue code (`C15` → 15, `B164` → 164); null when none. */
+export const numericSlotOfCode = (code) => {
+  const match = /([0-9]+)/.exec(code ?? '')
+  return match ? Number(match[1]) : null
+}
+
+/** Stable 32-bit FNV-1a hash → slot in [0, MAX_SLOT] for codes without digits. */
+export const hashSlotOf = (value) => {
+  let hash = 0x811c9dc5
+  for (const byte of Buffer.from(String(value), 'utf8')) {
+    hash ^= byte
+    hash = Math.imul(hash, 0x01000193) >>> 0
+  }
+  return hash % (MAX_SLOT + 1)
+}
+
+/** The slot a branch prefers before collision resolution. */
+const preferredSlotForBranch = (branch, code) => {
+  const numeric = numericSlotOfCode(code)
+  return numeric !== null && numeric <= MAX_SLOT ? numeric : hashSlotOf(branch)
+}
+
+export const devPortForSlot = (slot) => DEV_PORT_BASE + slot
+export const devDatabaseForSlot = (slot) => `teqo_wt${slot}`
+export const testDatabaseForSlot = (slot) => `teqo_wt${slot}_test`
+
+/** DB name charset guard — derived names are fed into `CREATE DATABASE` SQL. */
+export const isGeneratedDatabaseName = (name) => /^teqo_wt[0-9]+(_test)?$/.test(name ?? '')
+
+/**
+ * Final environment for a branch. `takenSlots` = slots already claimed by
+ * OTHER live worktrees; bumps +1 until free (bounded — live slot sets are
+ * tiny). Every value a consumer needs derives from the one final slot.
+ */
+export const worktreeEnvironment = ({ branch, code, takenSlots = new Set() }) => {
+  let slot = preferredSlotForBranch(branch, code)
+  while (takenSlots.has(slot)) slot += 1
+  return {
+    slot,
+    devPort: devPortForSlot(slot),
+    devDatabase: devDatabaseForSlot(slot),
+    testDatabase: testDatabaseForSlot(slot),
+  }
+}
diff --git a/scripts/worktree.mjs b/scripts/worktree.mjs
index 3ecf1899..986009fc 100644
--- a/scripts/worktree.mjs
+++ b/scripts/worktree.mjs
@@ -2,30 +2,55 @@
  * `pnpm worktree` — worktree management determinístico em torno da fila de
  * claim do projeto (mesma fila de `agent:claim` / agent pool).
  *
- *   pnpm worktree next [--go]      cria worktree a partir de origin/main para a
- *                                  próxima Issue claimável; branch `<code>-<slug>`.
- *                                  Com `--go`, imprime `cd <dir>` no fim — node
- *                                  não muda o cwd do shell pai; o shell chamador
- *                                  aplica (opencode/CDP usa o opencode command;
- *                                  terminal interativo: função `worktree()` em
- *                                  `.agents/shell/worktree.sh`, sourced no profile).
+ *   pnpm worktree next [--go] [--no-migrate]
+ *                              cria worktree a partir de origin/main para a
+ *                              próxima Issue claimável; branch `<code>-<slug>`.
+ *                              Com `--go`, imprime `cd <dir>` no fim — node
+ *                              não muda o cwd do shell pai; o shell chamador
+ *                              aplica (opencode/CDP usa o opencode command;
+ *                              terminal interativo: função `worktree()` em
+ *                              `.agents/shell/worktree.sh`, sourced no profile).
+ *                              Também PROVISIONA o ambiente isolado do worktree:
+ *                              porta do dev server + bancos próprios derivados
+ *                              deterministicamente do branch (ver
+ *                              scripts/lib/worktree-env.mjs), para agentes em
+ *                              paralelo não disputarem porta 3000 nem o
+ *                              `teqo_test` compartilhado. `--no-migrate` pula a
+ *                              aplicação das migrations nos bancos novos.
  *   pnpm worktree kill [--force]   destrói o worktree em que o shell atual está
- *                                  (recusa worktree sujo sem `--force`)
+ *                              (recusa worktree sujo sem `--force`) e remove os
+ *                              bancos gerados do worktree (best-effort)
  *
  * Read-only no GitHub: `next` NUNCA claima (claim = `pnpm agent:claim`).
  * Dir raiz: `~/.cursor/worktrees/teqo/` (mesma casa dos worktrees do Cursor).
  */
 
 import { execFileSync } from 'node:child_process'
+import { randomBytes } from 'node:crypto'
+import { existsSync, readFileSync, writeFileSync } from 'node:fs'
 import { homedir } from 'node:os'
 import { join, resolve } from 'node:path'
 
+import { parse as parseEnv } from 'dotenv'
+import pg from 'pg'
+
 import { dieAgent, nextClaimableIssue, parseArgs } from './lib/agent-github.mjs'
+import {
+  DEV_PORT_BASE,
+  GENERATED_ENV_MARKER,
+  isGeneratedDatabaseName,
+  worktreeEnvironment,
+} from './lib/worktree-env.mjs'
 import { branchNameForIssue } from './lib/worktree.mjs'
 
 const die = dieAgent('worktree')
 const WORKTREES_ROOT = join(homedir(), '.cursor', 'worktrees', 'teqo')
 
+/** Fixed compose project so `db:start`/provisioning always target ONE container. */
+const SHARED_COMPOSE_PROJECT = 'teqo'
+/** Maintenance database on the shared local container — only ever localhost. */
+const MAINTENANCE_DATABASE_URL = 'postgresql://teqo:teqo@localhost:5432/postgres'
+
 /** `git` wrapper; `okIfFails` swallows the failure and returns null instead. */
 const git = (args, { okIfFails = false } = {}) => {
   try {
@@ -56,7 +81,198 @@ const parseWorktreeList = (porcelain) => {
   return entries
 }
 
-const cmdNext = (go) => {
+/**
+ * Slots already claimed by OTHER live worktrees, read from their generated
+ * `.env.local` (only files carrying the marker count — manual envs claim
+ * nothing and are never overwritten).
+ */
+const readLiveSlots = (entries, excludedDir) => {
+  const slots = new Set()
+  for (const entry of entries) {
+    if (resolve(entry.path) === resolve(excludedDir)) continue
+    try {
+      const text = readFileSync(join(entry.path, '.env.local'), 'utf8')
+      if (!text.includes(GENERATED_ENV_MARKER)) continue
+      const match = /^PORT=([0-9]+)/m.exec(text)
+      const slot = match ? Number(match[1]) - DEV_PORT_BASE : null
+      if (slot !== null && Number.isInteger(slot) && slot >= 0) slots.add(slot)
+    } catch {
+      // worktree dir without a generated env file — nothing claimed
+    }
+  }
+  return slots
+}
+
+/** Merge the main repo's `.env` then `.env.local` (local wins) — secret source. */
+const readMainEnv = (mainRoot) => {
+  const merged = {}
+  for (const name of ['.env', '.env.local']) {
+    try {
+      Object.assign(merged, parseEnv(readFileSync(join(mainRoot, name), 'utf8')))
+    } catch {
+      // file missing — fine
+    }
+  }
+  return merged
+}
+
+const envFileIsGenerated = (dir, name) => {
+  try {
+    return readFileSync(join(dir, name), 'utf8').includes(GENERATED_ENV_MARKER)
+  } catch {
+    return false
+  }
+}
+
+/** Start (or reuse) the ONE shared Postgres container from any worktree dir. */
+const dockerComposeUp = (dir) => {
+  execFileSync(
+    'docker',
+    ['compose', '-p', SHARED_COMPOSE_PROJECT, 'up', '-d', '--wait', 'postgres'],
+    { cwd: dir, stdio: 'inherit' },
+  )
+}
+
+/** `CREATE DATABASE` for each missing generated name on the shared container. */
+const ensureDatabases = async (names) => {
+  const client = new pg.Client({
+    connectionString: MAINTENANCE_DATABASE_URL,
+    connectionTimeoutMillis: 5000,
+  })
+  await client.connect()
+  try {
+    for (const name of names) {
+      if (!isGeneratedDatabaseName(name)) die(`Nome de banco gerado inválido: ${name}`)
+      const { rows } = await client.query('SELECT 1 AS ok FROM pg_database WHERE datname = $1', [
+        name,
+      ])
+      if (rows.length > 0) {
+        console.log(`[worktree] banco ${name} já existe.`)
+        continue
+      }
+      await client.query(`CREATE DATABASE ${name}`)
+      console.log(`[worktree] banco criado: ${name}`)
+    }
+  } finally {
+    await client.end().catch(() => {})
+  }
+}
+
+const ensureWorktreeDeps = (dir) => {
+  if (existsSync(join(dir, 'node_modules', '.bin', 'payload'))) return
+  console.log('[worktree] ▶ node_modules ausente — pnpm install --frozen-lockfile …')
+  execFileSync('pnpm', ['install', '--frozen-lockfile'], { cwd: dir, stdio: 'inherit' })
+}
+
+const runMigrate = (dir, databaseUrl, payloadSecret) => {
+  console.log(`[worktree] ▶ migrations em ${databaseUrl} (uma vez por worktree)…`)
+  execFileSync('pnpm', ['migrate'], {
+    cwd: dir,
+    env: { ...process.env, DATABASE_URL: databaseUrl, PAYLOAD_SECRET: payloadSecret },
+    stdio: 'inherit',
+  })
+}
+
+/** Cursor Cloud / no-Docker fallback: shared teqo + teqo_test, no port override. */
+const writeFallbackEnv = (dir, branch) => {
+  const devEnv = [
+    GENERATED_ENV_MARKER,
+    '# fallback sem Docker (Cursor Cloud?): banco compartilhado, sem porta própria.',
+    `# branch ${branch}`,
+    'DATABASE_URL=postgresql://teqo:teqo@localhost:5432/teqo',
+    '',
+  ].join('\n')
+  const testEnv = [
+    GENERATED_ENV_MARKER,
+    '# fallback sem Docker (Cursor Cloud?): banco de teste compartilhado.',
+    `# branch ${branch}`,
+    'DATABASE_URL=postgresql://teqo:teqo@localhost:5432/teqo_test',
+    '',
+  ].join('\n')
+  writeFileSync(join(dir, '.env.local'), devEnv)
+  writeFileSync(join(dir, '.env.test.local'), testEnv)
+}
+
+/**
+ * Deterministic per-worktree environment: shared container + own databases +
+ * own dev-server port + env files + migrations. Skips everything when a
+ * manual `.env.local`/`.env.test.local` (no marker) exists — never clobbers.
+ */
+const provision = async ({ dir, branch, issue, env, skipMigrate, mainRoot }) => {
+  const manual =
+    (existsSync(join(dir, '.env.local')) && !envFileIsGenerated(dir, '.env.local')) ||
+    (existsSync(join(dir, '.env.test.local')) && !envFileIsGenerated(dir, '.env.test.local'))
+  if (manual) {
+    console.warn(
+      '[worktree] .env.local/.env.test.local manuais presentes — sem provisionar nem sobrescrever.',
+    )
+    console.warn(
+      '[worktree] Remova os arquivos manuais e rode `pnpm worktree next` de novo para o ambiente isolado.',
+    )
+    return
+  }
+
+  try {
+    dockerComposeUp(dir)
+  } catch (error) {
+    console.warn('[worktree] Docker indisponível — usando o banco compartilhado (teqo/teqo_test).')
+    console.warn(`[worktree] (${error.message.split('\n')[0]})`)
+    writeFallbackEnv(dir, branch)
+    return
+  }
+
+  const devDatabase = env.devDatabase
+  const testDatabase = env.testDatabase
+  const devUrl = `postgresql://teqo:teqo@localhost:5432/${devDatabase}`
+  const testUrl = `postgresql://teqo:teqo@localhost:5432/${testDatabase}`
+  await ensureDatabases([devDatabase, testDatabase])
+
+  const mainEnv = readMainEnv(mainRoot)
+  const payloadSecret = mainEnv.PAYLOAD_SECRET ?? randomBytes(24).toString('hex')
+  const copy = (key) => (mainEnv[key] ? [`${key}=${mainEnv[key]}`] : [])
+
+  const devEnv = [
+    GENERATED_ENV_MARKER,
+    `# branch ${branch} · issue #${issue.number} · slot ${env.slot} — gerado por pnpm worktree next`,
+    `DATABASE_URL=${devUrl}`,
+    `PORT=${env.devPort}`,
+    `NEXT_PUBLIC_SITE_URL=http://localhost:${env.devPort}`,
+    `PLAYWRIGHT_BASE_URL=http://localhost:${env.devPort}`,
+    `PAYLOAD_SECRET=${payloadSecret}`,
+    ...copy('BLOB_READ_WRITE_TOKEN'),
+    ...copy('NEXT_PUBLIC_VAPID_PUBLIC_KEY'),
+    ...copy('VAPID_PUBLIC_KEY'),
+    ...copy('VAPID_PRIVATE_KEY'),
+    ...copy('VAPID_SUBJECT'),
+    ...copy('RESEND_API_KEY'),
+    ...copy('CAMPAIGN_EMAIL_FROM'),
+    ...copy('CAMPAIGN_EMAIL_FROM_NAME'),
+    '',
+  ].join('\n')
+  writeFileSync(join(dir, '.env.local'), devEnv)
+  console.log(`[worktree] .env.local escrito (porta ${env.devPort}).`)
+
+  const testEnv = [
+    GENERATED_ENV_MARKER,
+    `# branch ${branch} · issue #${issue.number} · slot ${env.slot} — gerado por pnpm worktree next`,
+    '# Lido DEPOIS de .env.test (vitest.setup.ts / playwright.config.ts) — suites isoladas.',
+    `DATABASE_URL=${testUrl}`,
+    `NEXT_PUBLIC_SITE_URL=http://localhost:${env.devPort}`,
+    '',
+  ].join('\n')
+  writeFileSync(join(dir, '.env.test.local'), testEnv)
+  console.log('[worktree] .env.test.local escrito.')
+
+  if (skipMigrate) {
+    console.log('[worktree] --no-migrate: migrations ficam para depois (pnpm migrate).')
+    return
+  }
+  ensureWorktreeDeps(dir)
+  runMigrate(dir, devUrl, payloadSecret)
+  runMigrate(dir, testUrl, payloadSecret)
+}
+
+const cmdNext = async (go, skipMigrate) => {
   const pick = nextClaimableIssue()
   if (!pick) {
     die('Fila vazia — nada `ready` desbloqueado. Rode `pnpm agent:status` para ver a fila.')
@@ -89,10 +305,64 @@ const cmdNext = (go) => {
     console.log('Issue NÃO claimada — claim continua sendo `pnpm agent:claim`.')
   }
 
+  const mainRoot = entries[0]?.path
+  const env = worktreeEnvironment({
+    branch,
+    code: pick.meta.id,
+    takenSlots: readLiveSlots(entries, dir),
+  })
+  await provision({ dir, branch, issue, env, skipMigrate, mainRoot })
+
+  console.log(`\nAmbiente isolado do worktree (slot ${env.slot}):`)
+  console.log(`  dev server: http://localhost:${env.devPort}   (pnpm dev)`)
+  console.log(`  banco dev:  postgresql://teqo:teqo@localhost:5432/${env.devDatabase}`)
+  console.log(`  banco test: postgresql://teqo:teqo@localhost:5432/${env.testDatabase}`)
+
   if (go) console.log(`cd ${dir}`)
 }
 
-const cmdKill = (force) => {
+/** Generated database names referenced by a worktree's own env files. */
+const worktreeDatabaseNamesOf = (dir) => {
+  const names = []
+  for (const file of ['.env.local', '.env.test.local']) {
+    try {
+      const text = readFileSync(join(dir, file), 'utf8')
+      if (!text.includes(GENERATED_ENV_MARKER)) continue
+      for (const line of text.split('\n')) {
+        const match = /^DATABASE_URL=postgresql:\/\/[^/]+\/([a-z0-9_]+)$/.exec(line.trim())
+        if (match && isGeneratedDatabaseName(match[1])) names.push(match[1])
+      }
+    } catch {
+      // no env file — nothing to clean
+    }
+  }
+  return [...new Set(names)]
+}
+
+/** Best-effort DROP DATABASE (WITH FORCE) of the destroyed worktree's DBs. */
+const dropWorktreeDatabases = async (names) => {
+  if (names.length === 0) return
+  try {
+    const client = new pg.Client({
+      connectionString: MAINTENANCE_DATABASE_URL,
+      connectionTimeoutMillis: 5000,
+    })
+    await client.connect()
+    try {
+      for (const name of names) {
+        await client.query(`DROP DATABASE IF EXISTS ${name} WITH (FORCE)`)
+        console.log(`[worktree] banco removido: ${name}`)
+      }
+    } finally {
+      await client.end().catch(() => {})
+    }
+  } catch (error) {
+    console.warn(`[worktree] não consegui remover os bancos ${names.join(', ')}: ${error.message}`)
+    console.warn('[worktree] remova manualmente: docker exec teqo-postgres-1 dropdb -U teqo <nome>')
+  }
+}
+
+const cmdKill = async (force) => {
   const entries = parseWorktreeList(git(['worktree', 'list', '--porcelain']))
   const mainRoot = entries[0]?.path
   if (!mainRoot) die('Não consegui ler os worktrees deste repo.')
@@ -118,31 +388,39 @@ const cmdKill = (force) => {
     )
   }
 
+  // Read the generated DB names BEFORE the directory is removed.
+  const databaseNames = worktreeDatabaseNamesOf(top)
+
   git(['-C', mainRoot, 'worktree', 'remove', '--force', top])
   if (branch) git(['-C', mainRoot, 'branch', '-D', branch])
 
   console.log(`Worktree destruído: ${top}`)
   console.log(`  branch removido: ${branch ?? '(detached — nada a remover)'}`)
   console.log(`Volte ao main: cd ${mainRoot}`)
+
+  await dropWorktreeDatabases(databaseNames)
 }
 
 const { flags, positional } = parseArgs(process.argv.slice(2), new Set())
 const subcommand = positional[0]
 
 if (!subcommand) {
-  console.log('Uso: pnpm worktree next [--go] | kill [--force]')
-  console.log('  next [--go]     cria worktree da próxima Issue claimável (branch <code>-<slug>);')
-  console.log('                  com --go imprime `cd <dir>` no fim (quem aplica o cd: opencode')
-  console.log('                  command, ou a função `worktree()` de .agents/shell/worktree.sh)')
-  console.log('  kill [--force]  destrói o worktree em que você está (recusa sujo sem --force)')
+  console.log('Uso: pnpm worktree next [--go] [--no-migrate] | kill [--force]')
+  console.log('  next [--go] [--no-migrate]')
+  console.log('    cria worktree da próxima Issue claimável (branch <code>-<slug>) e provisiona o')
+  console.log('    ambiente isolado: porta de dev + bancos próprios (determinístico do branch);')
+  console.log('    com --go imprime `cd <dir>` no fim (quem aplica o cd: opencode command, ou a')
+  console.log('    função `worktree()` de .agents/shell/worktree.sh); --no-migrate pula migrations')
+  console.log('  kill [--force]  destrói o worktree em que você está (recusa sujo sem --force) e')
+  console.log('                  remove os bancos gerados do worktree (best-effort)')
   process.exit(1)
 }
 
 try {
-  if (subcommand === 'next') cmdNext(Boolean(flags.go))
+  if (subcommand === 'next') await cmdNext(Boolean(flags.go), Boolean(flags['no-migrate']))
   else if (subcommand === 'kill') {
     if (flags.go) die('`--go` só faz sentido com `next`.')
-    cmdKill(Boolean(flags.force))
+    await cmdKill(Boolean(flags.force))
   } else die(`subcomando desconhecido: ${subcommand} (esperado: next | kill)`)
 } catch (error) {
   if (error?.stderr) die(error.stderr.toString().trim())
diff --git a/tests/helpers/assertTestDatabase.ts b/tests/helpers/assertTestDatabase.ts
index 1717bc96..cbd83a38 100644
--- a/tests/helpers/assertTestDatabase.ts
+++ b/tests/helpers/assertTestDatabase.ts
@@ -3,14 +3,20 @@
  *
  * The tests delete and recreate records (see seedUser.ts), so they must NEVER
  * run against the production database. Rather than trying to detect prod (an
- * allowlist we could forget to update), we require the exact local test
- * database. A remote database is rejected even if its name looks test-like.
+ * allowlist we could forget to update), we require a LOCAL database whose name
+ * is `teqo_test` or `teqo_<worktree>_test` (per-worktree isolation generated
+ * by `pnpm worktree next`). A remote database is rejected even if its name
+ * looks test-like.
  */
+
+/** `teqo_test`, `teqo_wt15_test`, … — the _test suffix is the hard contract. */
+const TEST_DATABASE_NAME = /^teqo(_[a-z0-9]+)?_test$/
+
 export function assertTestDatabase(databaseUrl: string | undefined): void {
   if (!databaseUrl) {
     throw new Error(
-      'DATABASE_URL is not set. Tests require a dedicated test database configured in .env.test ' +
-        '(e.g. postgresql://teqo:teqo@localhost:5432/teqo_test).',
+      'DATABASE_URL is not set. Tests require a dedicated local test database configured in ' +
+        '.env.test (e.g. postgresql://teqo:teqo@localhost:5432/teqo_test).',
     )
   }
 
@@ -26,13 +32,14 @@ export function assertTestDatabase(databaseUrl: string | undefined): void {
 
   if (
     parsedUrl.protocol !== 'postgresql:' ||
-    databaseName !== 'teqo_test' ||
+    !TEST_DATABASE_NAME.test(databaseName) ||
     !localHosts.has(parsedUrl.hostname)
   ) {
     throw new Error(
       `Refusing to run tests using protocol "${parsedUrl.protocol || '(unknown)'}" against database ` +
         `"${databaseName || '(unknown)'}" on host ` +
-        `"${parsedUrl.hostname || '(unknown)'}". Tests require the exact database "teqo_test" ` +
+        `"${parsedUrl.hostname || '(unknown)'}". Tests require a local database named ` +
+        '`teqo_test` or `teqo_<worktree>_test` (per-worktree isolation from `pnpm worktree next`) ' +
         'over postgresql: on localhost, 127.0.0.1, or ::1. ' +
         'Configure DATABASE_URL in .env.test (e.g. postgresql://teqo:teqo@localhost:5432/teqo_test).',
     )
diff --git a/tests/int/assertTestDatabase.int.spec.ts b/tests/int/assertTestDatabase.int.spec.ts
index 3b08f174..7c2ae60b 100644
--- a/tests/int/assertTestDatabase.int.spec.ts
+++ b/tests/int/assertTestDatabase.int.spec.ts
@@ -5,17 +5,22 @@ import { assertTestDatabase } from '../helpers/assertTestDatabase'
 describe('assertTestDatabase', () => {
   it.each([
     'postgresql://teqo:teqo@localhost:5432/teqo_test',
+    'postgresql://teqo:teqo@localhost:5432/teqo_wt15_test',
     'postgresql://teqo:teqo@127.0.0.1:5432/teqo_test',
+    'postgresql://teqo:teqo@127.0.0.1:5432/teqo_wt164_test',
     'postgresql://teqo:teqo@[::1]:5432/teqo_test',
-  ])('accepts the exact local test database at %s', (databaseUrl) => {
+  ])('accepts the local test database at %s', (databaseUrl) => {
     expect(() => assertTestDatabase(databaseUrl)).not.toThrow()
   })
 
   it.each([
     'postgresql://teqo:teqo@localhost:5432/other_test',
     'postgresql://teqo:teqo@localhost:5432/teqo',
+    'postgresql://teqo:teqo@localhost:5432/teqo_wt15',
+    'postgresql://teqo:teqo@localhost:5432/teqo_test_extra',
+    'postgresql://teqo:teqo@localhost:5432/teqo_Test_test',
     'postgresql://teqo:teqo@db.example.com:5432/teqo_test',
-    'postgresql://teqo:teqo@neon.example.com:5432/other_test',
+    'postgresql://teqo:teqo@neon.example.com:5432/teqo_wt15_test',
     'postgres://teqo:teqo@localhost:5432/teqo_test',
     'https://localhost/teqo_test',
     'postgresql+srv://teqo:teqo@localhost:5432/teqo_test',
diff --git a/tests/unit/worktree.unit.spec.ts b/tests/unit/worktree.unit.spec.ts
index 0e375897..f11087c5 100644
--- a/tests/unit/worktree.unit.spec.ts
+++ b/tests/unit/worktree.unit.spec.ts
@@ -2,6 +2,16 @@
 
 import { describe, expect, it } from 'vitest'
 
+import {
+  GENERATED_ENV_MARKER,
+  devDatabaseForSlot,
+  devPortForSlot,
+  hashSlotOf,
+  isGeneratedDatabaseName,
+  numericSlotOfCode,
+  testDatabaseForSlot,
+  worktreeEnvironment,
+} from '../../scripts/lib/worktree-env.mjs'
 import { branchNameForIssue, issueCodeAndSubject } from '../../scripts/lib/worktree.mjs'
 
 type TestIssue = {
@@ -67,3 +77,70 @@ describe('branchNameForIssue', () => {
     )
   })
 })
+
+describe('worktreeEnvironment (per-worktree ports and databases)', () => {
+  it('derives slot, port and database names deterministically from the branch', () => {
+    const env = worktreeEnvironment({ branch: 'C15-foo', code: 'C15' })
+    expect(env).toEqual(worktreeEnvironment({ branch: 'C15-foo', code: 'C15' }))
+    expect(env).toEqual({
+      slot: 15,
+      devPort: 3115,
+      devDatabase: 'teqo_wt15',
+      testDatabase: 'teqo_wt15_test',
+    })
+  })
+
+  it('uses the numeric part of the issue code as the preferred slot', () => {
+    expect(numericSlotOfCode('C15')).toBe(15)
+    expect(numericSlotOfCode('B164')).toBe(164)
+    expect(numericSlotOfCode('P3')).toBe(3)
+    expect(numericSlotOfCode('E2')).toBe(2)
+  })
+
+  it('falls back to a stable hash slot for codes without digits', () => {
+    expect(numericSlotOfCode('X')).toBeNull()
+    const env = worktreeEnvironment({ branch: 'X-foo', code: 'X' })
+    expect(env.slot).toBeGreaterThanOrEqual(0)
+    expect(env.slot).toBeLessThanOrEqual(999)
+    expect(env).toEqual(worktreeEnvironment({ branch: 'X-foo', code: 'X' }))
+    expect(hashSlotOf('X-foo')).toBe(hashSlotOf('X-foo'))
+  })
+
+  it('bumps to the next free slot when the preferred one is taken', () => {
+    const env = worktreeEnvironment({
+      branch: 'A15-bar',
+      code: 'A15',
+      takenSlots: new Set([15, 16]),
+    })
+    expect(env.slot).toBe(17)
+    expect(env.devPort).toBe(3117)
+    expect(env.devDatabase).toBe('teqo_wt17')
+    expect(env.testDatabase).toBe('teqo_wt17_test')
+  })
+
+  it('keeps port and database names consistent after a bump', () => {
+    const env = worktreeEnvironment({ branch: 'C15-foo', code: 'C15', takenSlots: new Set([15]) })
+    expect(devPortForSlot(env.slot)).toBe(env.devPort)
+    expect(devDatabaseForSlot(env.slot)).toBe(env.devDatabase)
+    expect(testDatabaseForSlot(env.slot)).toBe(env.testDatabase)
+  })
+
+  it('caps huge codes into the hash range instead of absurd ports', () => {
+    const env = worktreeEnvironment({ branch: 'C999999-foo', code: 'C999999' })
+    expect(env.slot).toBeLessThanOrEqual(999)
+    expect(env.devPort).toBeLessThanOrEqual(4099)
+  })
+
+  it('accepts only generated names for CREATE/DROP DATABASE', () => {
+    expect(isGeneratedDatabaseName('teqo_wt15')).toBe(true)
+    expect(isGeneratedDatabaseName('teqo_wt15_test')).toBe(true)
+    expect(isGeneratedDatabaseName('teqo')).toBe(false)
+    expect(isGeneratedDatabaseName('teqo_test')).toBe(false)
+    expect(isGeneratedDatabaseName('teqo_wt15_extra')).toBe(false)
+    expect(isGeneratedDatabaseName('teqo_wt15_test; DROP TABLE x')).toBe(false)
+  })
+
+  it('pins the marker used to detect generated env files', () => {
+    expect(GENERATED_ENV_MARKER).toContain('generated by pnpm worktree next')
+  })
+})
diff --git a/vitest.setup.ts b/vitest.setup.ts
index b3a11617..761779bc 100644
--- a/vitest.setup.ts
+++ b/vitest.setup.ts
@@ -6,6 +6,9 @@ import { config as loadEnv } from 'dotenv'
 import { assertTestDatabase } from './tests/helpers/assertTestDatabase'
 
 loadEnv({ path: '.env.test', override: true })
+// Per-worktree isolation: `.env.test.local` (gitignored, written by
+// `pnpm worktree next`) wins over the committed `.env.test` when present.
+loadEnv({ path: '.env.test.local', override: true })
 
 // Optional local override when the default Docker port is occupied (e.g. mapped to 5433).
 if (process.env.TEQO_TEST_DATABASE_URL) {