P3-A: worktrees multi-repo & cycle de vie (backend)

Enregistrement de repos et gestion de leurs worktrees git, source de vérité
= git (worktrees dérivés + cache court par repo), corrélation worktree ↔
sessions par cwd, mutations sérialisées par repo.

- shared: RepoSummary, PostCreateHook, WorktreeSummary, WorktreeGitStatus ;
  messages WS repo_update/worktree_update/*_removed ; topic sub 'worktrees'
  (+ parseClientMessage) ; DTOs REST repos/worktrees.
- db: migration id:3 (table repos).
- core/git.ts: couche git sûre (execFile, jamais de shell, -- avant chemins,
  GIT_OPTIONAL_LOCKS=0), parseWorktreePorcelain, list/add/remove/prune/status/
  ahead-behind, validation branche + chemin.
- core/claude-trust.ts: pré-trust atomique de ~/.claude.json (spike S3).
- core/worktree-manager.ts: repos CRUD, create (worktree add + pré-trust +
  hooks post-create + startSession optionnel), adopt, delete (garde-fous 409
  dirty / 400 main / 409 session live), prune ; events.
- routes/repos.ts + routes/worktrees.ts, câblage app.ts, gateway topic worktrees.
- tests: git (repos tmp réels), claude-trust, worktree-manager (146 verts).

packages/server/src/routes/worktrees.ts

@@ -0,0 +1,88 @@
+import type { FastifyInstance } from 'fastify';
+import type {
+  AdoptWorktreeRequest,
+  CreateWorktreeRequest,
+  CreateWorktreeResponse,
+  WorktreeResponse,
+  WorktreesListResponse,
+} from '@arboretum/shared';
+import type { WorktreeManager } from '../core/worktree-manager.js';
+import { sendManagerError } from './repos.js';
+
+export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager): void {
+  app.get('/api/v1/worktrees', async (): Promise<WorktreesListResponse> => ({ worktrees: await wt.listAllWorktrees() }));
+
+  app.get('/api/v1/repos/:id/worktrees', async (req): Promise<WorktreesListResponse> => {
+    const { id } = req.params as { id: string };
+    return { worktrees: await wt.listRepoWorktrees(id) };
+  });
+
+  app.post('/api/v1/repos/:id/worktrees', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const body = req.body as Partial<CreateWorktreeRequest> | null;
+    if (!body || typeof body.branch !== 'string' || body.branch.trim() === '') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'branch is required' } });
+    }
+    if (body.startSession != null && body.startSession !== 'claude' && body.startSession !== 'bash') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'startSession must be claude, bash or null' } });
+    }
+    try {
+      const out = await wt.createWorktree(id, {
+        branch: body.branch,
+        newBranch: body.newBranch !== false, // défaut : créer la branche
+        ...(body.baseRef !== undefined ? { baseRef: body.baseRef } : {}),
+        ...(body.path !== undefined ? { path: body.path } : {}),
+        ...(body.runHooks !== undefined ? { runHooks: body.runHooks } : {}),
+        ...(body.preTrust !== undefined ? { preTrust: body.preTrust } : {}),
+        ...(body.startSession !== undefined ? { startSession: body.startSession } : {}),
+      });
+      const res: CreateWorktreeResponse = out;
+      return reply.status(201).send(res);
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
+  app.post('/api/v1/repos/:id/worktrees/adopt', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const body = req.body as Partial<AdoptWorktreeRequest> | null;
+    if (!body || typeof body.path !== 'string') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'path is required' } });
+    }
+    try {
+      const out = await wt.adoptWorktree(id, {
+        path: body.path,
+        ...(body.runHooks !== undefined ? { runHooks: body.runHooks } : {}),
+        ...(body.preTrust !== undefined ? { preTrust: body.preTrust } : {}),
+      });
+      const res: WorktreeResponse & { hookResults: typeof out.hookResults } = { worktree: out.worktree, hookResults: out.hookResults };
+      return reply.send(res);
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
+  app.post('/api/v1/repos/:id/worktrees/prune', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    try {
+      await wt.prune(id);
+      return reply.send({ ok: true });
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
+  app.delete('/api/v1/repos/:id/worktrees', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const query = req.query as { path?: string; force?: string };
+    if (typeof query.path !== 'string') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'path query param is required' } });
+    }
+    try {
+      await wt.deleteWorktree(id, query.path, query.force === 'true');
+      return reply.send({ ok: true });
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+}