feat(worktrees): création intelligente (auto) + commit/push/promotion + grille agrandissable

- addWorktree résout la branche par dépôt (branchExists) : checkout si présente, suivi de origin/<b> si seulement remote, sinon création (-b) depuis la branche par défaut. Corrige le 'fatal: invalid reference' sur les groupes hétérogènes ; newBranch -> mode (déprécié, mappé en route).
- Nouvelles opérations git : commit (add -A), push (upstream auto), promotion « en principal » (la branche du worktree devient le checkout principal, sans merge ni conflit, ancienne branche conservée). Routes /worktrees/{commit,push,promote} auditées + GET /repos/:id/branches.
- Web : actions Commit/Push/Promouvoir sur WorktreeCard, sélecteur de branche de base (datalist) dans RepoSection et GroupSessionModal, agrandissement d'un terminal au choix dans TerminalGrid.
- Court-circuite la session de groupe quand aucun worktree n'a pu être créé (fini le masquage par « no resolvable worktree »).
- Tests : git.ts (branchExists/listBranches/commitAll/auto), worktree-manager (commit/promote/branches) ; acceptance P5 étend le scénario worktree de groupe sur branche neuve + commit + promotion.

packages/server/src/routes/groups.ts

@@ -139,7 +139,8 @@ export function registerGroupRoutes(
     }
 
     if (dirs.length === 0) {
-      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'no directory to span (group has no resolvable worktree)' } });
+      const detail = branch ? `no repo has a worktree on branch "${branch}" (create it first)` : 'no repo has a resolvable main checkout';
+      return reply.status(400).send({ error: { code: 'NO_RESOLVABLE_WORKTREE', message: `Cannot start group session: ${detail}` } });
     }
     // cwd = parent commun des repos couverts, chacun relié en --add-dir (P6). Voir resolveGroupCwd.
     const { cwd, addDirs } = resolveGroupCwd(dirs);

packages/server/src/routes/worktrees.ts

@@ -1,17 +1,32 @@
 import type { FastifyInstance } from 'fastify';
 import type {
   AdoptWorktreeRequest,
+  CommitWorktreeRequest,
   CreateWorktreeRequest,
   CreateWorktreeResponse,
+  PromoteWorktreeRequest,
+  PushWorktreeRequest,
+  RepoBranchesResponse,
   SessionResponse,
   StartRepoSessionRequest,
+  WorktreeBranchMode,
   WorktreeResponse,
   WorktreesListResponse,
 } from '@arboretum/shared';
 import type { WorktreeManager } from '../core/worktree-manager.js';
+import type { Db } from '../db/index.js';
+import { recordAudit } from '../core/audit-log.js';
 import { sendManagerError } from './repos.js';
 
-export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager): void {
+/** Mappe l'API (mode prioritaire ; `newBranch` déprécié) vers la stratégie de résolution de branche. */
+function resolveMode(body: { mode?: unknown; newBranch?: unknown }): WorktreeBranchMode {
+  if (body.mode === 'auto' || body.mode === 'create' || body.mode === 'checkout') return body.mode;
+  if (body.newBranch === true) return 'create';
+  if (body.newBranch === false) return 'checkout';
+  return 'auto';
+}
+
+export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager, db: Db): void {
   app.get('/api/v1/worktrees', async (): Promise<WorktreesListResponse> => ({ worktrees: await wt.listAllWorktrees() }));
 
   app.get('/api/v1/repos/:id/worktrees', async (req): Promise<WorktreesListResponse> => {
@@ -31,7 +46,7 @@ export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager
     try {
       const out = await wt.createWorktree(id, {
         branch: body.branch,
-        newBranch: body.newBranch !== false, // défaut : créer la branche
+        mode: resolveMode(body), // défaut : auto (détecte créer / checkout / suivi remote)
         ...(body.baseRef !== undefined ? { baseRef: body.baseRef } : {}),
         ...(body.path !== undefined ? { path: body.path } : {}),
         ...(body.runHooks !== undefined ? { runHooks: body.runHooks } : {}),
@@ -45,6 +60,17 @@ export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager
     }
   });
 
+  // Branches du repo (locales + suivies de origin + défaut) — alimente le sélecteur de base côté UI.
+  app.get('/api/v1/repos/:id/branches', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    try {
+      const out = await wt.listRepoBranches(id);
+      return reply.send(out satisfies RepoBranchesResponse);
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
   // Session sur le checkout principal (« bosser sur la branche principale » sans worktree),
   // avec création/bascule de branche optionnelle côté serveur.
   app.post('/api/v1/repos/:id/session', async (req, reply) => {
@@ -101,6 +127,57 @@ export function registerWorktreeRoutes(app: FastifyInstance, wt: WorktreeManager
     }
   });
 
+  // Commit (git add -A + commit) dans un worktree (ou le checkout principal).
+  app.post('/api/v1/repos/:id/worktrees/commit', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const body = req.body as Partial<CommitWorktreeRequest> | null;
+    if (!body || typeof body.path !== 'string') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'path is required' } });
+    }
+    if (typeof body.message !== 'string' || body.message.trim() === '') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'message is required' } });
+    }
+    try {
+      const worktree = await wt.commitWorktree(id, body.path, body.message.trim());
+      recordAudit(db, { actor: req.authContext?.tokenId ?? 'unknown', action: 'worktree.commit', resourceId: id, details: { path: body.path } });
+      return reply.send({ worktree } satisfies WorktreeResponse);
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
+  // Push de la branche d'un worktree (upstream auto si absent).
+  app.post('/api/v1/repos/:id/worktrees/push', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const body = req.body as Partial<PushWorktreeRequest> | null;
+    if (!body || typeof body.path !== 'string') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'path is required' } });
+    }
+    try {
+      const worktree = await wt.pushWorktree(id, body.path);
+      recordAudit(db, { actor: req.authContext?.tokenId ?? 'unknown', action: 'worktree.push', resourceId: id, details: { path: body.path } });
+      return reply.send({ worktree } satisfies WorktreeResponse);
+    } catch (err) {
+      return sendManagerError(reply, err);
+    }
+  });
+
+  // Promotion « en principal » : la branche du worktree devient le checkout principal (worktree supprimé).
+  app.post('/api/v1/repos/:id/worktrees/promote', async (req, reply) => {
+    const { id } = req.params as { id: string };
+    const body = req.body as Partial<PromoteWorktreeRequest> | null;
+    if (!body || typeof body.path !== 'string') {
+      return reply.status(400).send({ error: { code: 'BAD_REQUEST', message: 'path is required' } });
+    }
+    try {
+      const worktree = await wt.promoteWorktree(id, body.path, body.force === true);
+      recordAudit(db, { actor: req.authContext?.tokenId ?? 'unknown', action: 'worktree.promote', resourceId: id, details: { path: body.path } });
+      return reply.send({ worktree });
+    } 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 };