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/web/src/components/WorktreeCard.vue

@@ -62,6 +62,41 @@
       </div>
     </div>
 
+    <!-- actions git : commit / push / promotion en principal (sans ouvrir le terminal) -->
+    <div v-if="canPush || worktree.git.dirtyCount || canPromote" class="mt-1 flex flex-wrap items-center gap-2">
+      <form v-if="committingOpen" class="flex flex-wrap items-center gap-1" @submit.prevent="onCommit">
+        <input v-model="commitMessage" class="input w-44 text-xs" :placeholder="t('worktrees.commitPlaceholder')" />
+        <button type="submit" class="btn-primary text-xs" :disabled="!!gitBusy || commitMessage.trim() === ''">
+          {{ gitBusy === 'commit' ? t('worktrees.committing') : t('worktrees.commit') }}
+        </button>
+        <button type="button" class="btn text-xs" @click="committingOpen = false">{{ t('common.cancel') }}</button>
+      </form>
+      <button v-else-if="worktree.git.dirtyCount" class="btn text-xs" :disabled="!!gitBusy" @click="committingOpen = true">
+        {{ t('worktrees.commit') }}
+      </button>
+
+      <button v-if="canPush" class="btn text-xs" :disabled="!!gitBusy" @click="onPush">
+        {{ gitBusy === 'push' ? t('worktrees.pushing') : t('worktrees.push') }}<span v-if="worktree.git.ahead"> ↑{{ worktree.git.ahead }}</span>
+      </button>
+
+      <button v-if="canPromote && !promoteConfirming" class="btn text-xs" :disabled="!!gitBusy" @click="promoteConfirming = true">
+        {{ t('worktrees.promote') }}
+      </button>
+
+      <span v-if="gitError" class="text-xs text-amber-400">{{ gitError }}</span>
+    </div>
+
+    <!-- confirmation explicite de la promotion (action destructive : ce worktree sera supprimé) -->
+    <div v-if="promoteConfirming" class="mt-1 rounded border border-amber-700/40 bg-amber-950/20 p-2 text-xs text-amber-200">
+      {{ promoteConfirmText }}
+      <div class="mt-1 flex items-center gap-2">
+        <button class="btn-primary text-xs" :disabled="!!gitBusy" @click="onPromote">
+          {{ gitBusy === 'promote' ? t('worktrees.promoting') : forcePromoteNeeded ? t('worktrees.forcePromote') : t('worktrees.promote') }}
+        </button>
+        <button class="btn text-xs" @click="cancelPromote">{{ t('common.cancel') }}</button>
+      </div>
+    </div>
+
     <!-- réponse rapide aux dialogues des sessions corrélées en attente (sans ouvrir le terminal) -->
     <DialogPrompt v-for="ws in waitingSessions" :key="`dlg-${ws.id}`" :session="ws" class="mt-2" />
   </div>
@@ -135,6 +170,73 @@ const branchLabel = computed(() =>
   props.worktree.branch ?? (props.worktree.detached ? `${t('worktrees.detached')} ${props.worktree.head.slice(0, 7)}` : '—'),
 );
 
+// --- actions git : commit / push / promotion en principal ---
+const gitBusy = ref<null | 'commit' | 'push' | 'promote'>(null);
+const gitError = ref<string | null>(null);
+const committingOpen = ref(false);
+const commitMessage = ref('');
+const promoteConfirming = ref(false);
+const forcePromoteNeeded = ref(false);
+
+const canPush = computed(() => !!props.worktree.branch && !props.worktree.detached);
+const canPromote = computed(() => !props.worktree.isMain && !!props.worktree.branch && !props.worktree.detached);
+const promoteConfirmText = computed(() => t('worktrees.promoteConfirm', { branch: props.worktree.branch ?? '' }));
+
+function gitMsg(err: unknown): string {
+  return err instanceof Error ? err.message : String(err);
+}
+function cancelPromote(): void {
+  promoteConfirming.value = false;
+  forcePromoteNeeded.value = false;
+}
+
+async function onCommit(): Promise<void> {
+  if (gitBusy.value || commitMessage.value.trim() === '') return;
+  gitBusy.value = 'commit';
+  gitError.value = null;
+  try {
+    await store.commitWorktree(props.worktree.repoId, props.worktree.path, commitMessage.value.trim());
+    committingOpen.value = false;
+    commitMessage.value = '';
+  } catch (err) {
+    gitError.value = gitMsg(err);
+  } finally {
+    gitBusy.value = null;
+  }
+}
+
+async function onPush(): Promise<void> {
+  if (gitBusy.value) return;
+  gitBusy.value = 'push';
+  gitError.value = null;
+  try {
+    await store.pushWorktree(props.worktree.repoId, props.worktree.path);
+  } catch (err) {
+    gitError.value = gitMsg(err);
+  } finally {
+    gitBusy.value = null;
+  }
+}
+
+async function onPromote(): Promise<void> {
+  if (gitBusy.value) return;
+  gitBusy.value = 'promote';
+  gitError.value = null;
+  try {
+    await store.promoteWorktree(props.worktree.repoId, props.worktree.path, forcePromoteNeeded.value);
+    // succès : la branche est passée en principal et ce worktree est supprimé → la carte se démonte.
+  } catch (err) {
+    if (err instanceof ApiError && err.status === 409) {
+      forcePromoteNeeded.value = true; // arbre modifié → proposer la promotion forcée
+      gitError.value = err.message;
+    } else {
+      gitError.value = gitMsg(err);
+    }
+  } finally {
+    gitBusy.value = null;
+  }
+}
+
 function reset(): void {
   confirming.value = false;
   forceNeeded.value = false;