feat: conversation list + manage for "Ask your library" (P13d-2b)

docs/BACKLOG.md

@@ -8,6 +8,12 @@
 _(nothing active — pick the next batch from below)_
 
 ## Deferred / future refinements
+- [ ] **GraphRAG — search/filter conversations.** The chat list (P13d-2b) shows every active chat; once a user
+      accumulates many, add a search field (by title/preview) and/or pinning. *(From P13d-2b.)*
+- [ ] **GraphRAG — bulk chat management + swipe gestures.** Multi-select archive/delete and a swipe-to-archive
+      gesture on list rows (today each action is a per-row overflow-menu tap + confirm). *(From P13d-2b.)*
+- [ ] **GraphRAG — refresh a chat's title from its content.** The title is derived once from the first question
+      (renamable); consider an LLM/heuristic re-title as a conversation evolves. *(From P13d-2b.)*
 - [ ] **GraphRAG — store only the *cited* sources.** P13d-2a persists **all** retrieved sources as a turn's
       citations (and renders every `[n]` the model emits); it doesn't prune to the subset the answer actually
       cites. If answers reference few sources, post-parse the `[n]` markers and persist only those (smaller

docs/VERIFICATION.md

@@ -1003,6 +1003,17 @@ entries, or verify after P11c lands.)*
 - [ ] With generation **not** set up (eligible device, no model), sending shows the **on-ramp** snackbar and
       routes to AI settings.
 
+### P13d-2b — Conversation list + manage  *(install `app-arm64-v8a-debug.apk`; needs a capable device + a downloaded generation model)*
+- [ ] Ask questions in **two separate chats** (open Ask → New chat each time) → the Dashboard "Ask" entry now
+      opens a **conversation list** showing both, **most-recent-first**, each with a **preview** of its last
+      message and a relative time.
+- [ ] **Reopen** a chat from the list → its prior turns show, and a **new question continues with retained
+      context** (the answer reflects the earlier turns) — **fully offline**.
+- [ ] **Rename** a chat (row menu → Rename) → the new title persists in the list and on the open chat's app bar.
+- [ ] **Archive** a chat → it leaves the main list; it appears under **Archived chats** (app-bar overflow) and
+      can be **Unarchived** back; **Delete** removes a chat (and its messages) for good (after a confirm).
+- [ ] With no chats yet, the list shows an **empty state** whose CTA starts a chat.
+
 ### P13 (later subphases)
 - [ ] **Transcription / summarization / translation / OCR** each work (capability-gated) and write
       results back to the item.

docs/design/P13-PLAN.md

@@ -258,11 +258,22 @@ Incapable / low tiers fall back to an ephemeral **retrieval-only** answer (d-3).
 - **Exit / review:** ask a natural-language question on a capable device → a streamed, grounded, cited answer
   **offline**; the turn persists; citations navigate. APK spot-check. ✓ (CI parts) · APK owed
 
-#### `[ ]` P13d-2b — Conversation list + manage *(native)*
+#### `[~]` P13d-2b — Conversation list + manage *(native)*
 - A conversation **list** with **continue / rename / archive / delete**; resuming a chat re-feeds the bounded
   history into each new turn's prompt.
+- **Status:** implemented (CI-green; APK spot-check owed). **List-first** entry — the Dashboard tile (`/ask`)
+  now opens a **`ConversationsScreen`** (most-recent-first, "New chat" FAB, empty-state CTA), with continue
+  (`/ask/chat/:id`), new chat (`/ask/chat`), and an **`ArchivedChatsScreen`** (`/ask/archived`). `ChatRepository`
+  gains `watchChatList({archived})` (one query with a latest-message preview subquery), `renameChat`,
+  `setArchived`, `deleteChat` (messages cascade), `watchChatTitle` + `activeChatsProvider`/`archivedChatsProvider`/
+  `chatTitleProvider`. `AskController` is now a **family keyed by `String? chatId`** — a seeded id continues a
+  thread (history feeds back), `null` creates on first send (the d-2a behaviour); `AskScreen` takes `chatId` and
+  shows the live, renamable title. **No schema change** (v14 already carried `title`/`archivedAt`); no new deps.
+  Tests: repo (recency/preview ordering, active-vs-archived split, archive toggle, rename incl. blank-ignored,
+  cascade delete), the resumable controller (continue feeds prior turns; no new chat), and a `ConversationsScreen`
+  widget test (rows/preview, empty-state CTA, row Rename/Archive/Delete menu).
 - **Exit / review:** prior chats list, reopen and continue with retained context, and archive/delete/rename
-  behave; covered where CI can (provider/repository) + an APK spot-check for the flow.
+  behave; covered where CI can (provider/repository) + an APK spot-check for the flow. ✓ (CI parts) · APK owed
 
 #### `[ ]` P13d-3 — Low-tier fallback + tier-aware depth + RAM co-residency *(native; APK)*
 - On ineligible / low tiers (`ragAvailability == retrievalOnly`), fall back to an ephemeral **retrieval-only**

lib/core/routing/app_router.dart

@@ -13,6 +13,7 @@ import 'package:grabbit/features/library/presentation/entity_hub_screen.dart';
 import 'package:grabbit/features/library/presentation/home_screen.dart';
 import 'package:grabbit/features/library/presentation/item_detail_screen.dart';
 import 'package:grabbit/features/ai/presentation/ask_screen.dart';
+import 'package:grabbit/features/ai/presentation/conversations_screen.dart';
 import 'package:grabbit/features/ai/presentation/graph_view_screen.dart';
 import 'package:grabbit/features/library/presentation/media_studio_screen.dart';
 import 'package:grabbit/features/library/presentation/metadata_edit_screen.dart';
@@ -259,8 +260,29 @@ GoRouter appRouter(Ref ref) {
         path: '/ask',
         name: 'ask',
         parentNavigatorKey: _rootNavigatorKey,
+        builder: (context, state) => const ConversationsScreen(),
+      ),
+      // Static `/ask/chat` is registered before the `:id` route so a new chat
+      // never matches as a conversation id.
+      GoRoute(
+        path: '/ask/chat',
+        name: 'ask-new',
+        parentNavigatorKey: _rootNavigatorKey,
         builder: (context, state) => const AskScreen(),
       ),
+      GoRoute(
+        path: '/ask/chat/:id',
+        name: 'ask-chat',
+        parentNavigatorKey: _rootNavigatorKey,
+        builder: (context, state) =>
+            AskScreen(chatId: state.pathParameters['id']),
+      ),
+      GoRoute(
+        path: '/ask/archived',
+        name: 'ask-archived',
+        parentNavigatorKey: _rootNavigatorKey,
+        builder: (context, state) => const ArchivedChatsScreen(),
+      ),
     ],
   );
 }

lib/features/ai/data/chat_repository.dart

@@ -3,10 +3,30 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:grabbit/core/db/database.dart';
 import 'package:grabbit/core/db/database_provider.dart';
 
-/// Persistence for the "Ask your library" GraphRAG chat (P13d-2a): a thread of
+/// A conversation as shown in the chat list (P13d-2b): the chat's id/title, when
+/// it was last touched, the latest message as a preview, and whether it's
+/// archived. A lightweight projection (not the full [Chat] row) so the list query
+/// stays a single statement with no per-row follow-up reads.
+class ChatListItem {
+  const ChatListItem({
+    required this.id,
+    required this.title,
+    required this.updatedAt,
+    required this.preview,
+    required this.archived,
+  });
+
+  final String id;
+  final String title;
+  final DateTime updatedAt;
+  final String? preview;
+  final bool archived;
+}
+
+/// Persistence for the "Ask your library" GraphRAG chat (P13d-2a/b): a thread of
 /// [Chat]s, each a list of ordered [ChatMessage]s. Drift stays canonical; this
-/// repo only reads/writes the `chats` + `chat_messages` tables. The conversation
-/// list + rename/archive/delete land in d-2b on the same schema.
+/// repo only reads/writes the `chats` + `chat_messages` tables. d-2b adds the
+/// conversation list + rename/archive/delete on the same v14 schema.
 class ChatRepository {
   ChatRepository(this._db);
 
@@ -71,6 +91,68 @@ class ChatRepository {
             ..where((t) => t.chatId.equals(chatId))
             ..orderBy([(t) => OrderingTerm.asc(t.id)]))
           .get();
+
+  /// Live conversation list (P13d-2b), most-recent-first, filtered by
+  /// [archived]. One reactive statement with a correlated subquery for each
+  /// chat's latest message (the list preview) — no per-row follow-up reads.
+  Stream<List<ChatListItem>> watchChatList({required bool archived}) {
+    final archivedClause = archived
+        ? 'archived_at IS NOT NULL'
+        : 'archived_at IS NULL';
+    return _db
+        .customSelect(
+          // `chats.*` so Drift's generated mapper decodes the row (incl. the
+          // DateTime format); `preview` is the latest message via a correlated
+          // subquery — one statement, no per-row follow-up read.
+          'SELECT chats.*, '
+          '(SELECT content FROM chat_messages m WHERE m.chat_id = chats.id '
+          'ORDER BY m.id DESC LIMIT 1) AS preview '
+          'FROM chats WHERE $archivedClause ORDER BY updated_at DESC',
+          readsFrom: {_db.chats, _db.chatMessages},
+        )
+        .watch()
+        .map((rows) {
+          return rows.map((row) {
+            final chat = _db.chats.map(row.data);
+            return ChatListItem(
+              id: chat.id,
+              title: chat.title,
+              updatedAt: chat.updatedAt,
+              preview: row.read<String?>('preview'),
+              archived: archived,
+            );
+          }).toList();
+        });
+  }
+
+  /// Live title for [chatId] (null if the chat doesn't exist yet) — drives the
+  /// chat screen's app bar so a rename reflects immediately.
+  Stream<String?> watchChatTitle(String chatId) =>
+      (_db.select(_db.chats)..where((t) => t.id.equals(chatId)))
+          .watchSingleOrNull()
+          .map((c) => c?.title);
+
+  /// Renames [chatId]; a blank title is ignored (keeps the derived one).
+  Future<void> renameChat(String chatId, String title) async {
+    final trimmed = title.trim();
+    if (trimmed.isEmpty) return;
+    await (_db.update(_db.chats)..where((t) => t.id.equals(chatId))).write(
+      ChatsCompanion(title: Value(trimmed)),
+    );
+  }
+
+  /// Archives (hides from the active list, kept + restorable) or unarchives
+  /// [chatId] by setting/clearing `archivedAt`.
+  Future<void> setArchived(String chatId, bool archived) async {
+    await (_db.update(_db.chats)..where((t) => t.id.equals(chatId))).write(
+      ChatsCompanion(archivedAt: Value(archived ? DateTime.now() : null)),
+    );
+  }
+
+  /// Deletes [chatId]; its messages cascade (the `chat_messages` FK).
+  Future<void> deleteChat(String chatId) async {
+    await (_db.delete(_db.chats)..where((t) => t.id.equals(chatId))).go();
+  }
 }
 
 final chatRepositoryProvider = Provider<ChatRepository>(
@@ -82,3 +164,19 @@ final chatRepositoryProvider = Provider<ChatRepository>(
 final chatMessagesProvider = StreamProvider.family<List<ChatMessage>, String>(
   (ref, chatId) => ref.watch(chatRepositoryProvider).watchMessages(chatId),
 );
+
+/// Active (non-archived) conversations for the chat list (P13d-2b),
+/// most-recent-first.
+final activeChatsProvider = StreamProvider<List<ChatListItem>>(
+  (ref) => ref.watch(chatRepositoryProvider).watchChatList(archived: false),
+);
+
+/// Archived conversations (kept + restorable), most-recent-first.
+final archivedChatsProvider = StreamProvider<List<ChatListItem>>(
+  (ref) => ref.watch(chatRepositoryProvider).watchChatList(archived: true),
+);
+
+/// Live title of a single conversation, for the chat screen's app bar.
+final chatTitleProvider = StreamProvider.family<String?, String>(
+  (ref, chatId) => ref.watch(chatRepositoryProvider).watchChatTitle(chatId),
+);

lib/features/ai/presentation/ask_controller.dart

@@ -25,10 +25,14 @@ class AskState {
 /// grounded answer through the local LLM, and persists the turn with its
 /// citations. No sources → a graceful "couldn't find" reply, no LLM call. The
 /// caller gates on generation readiness (`aiSummaryAction`) before [send].
+///
+/// Keyed by [chatId] (P13d-2b): a non-null id **continues** that conversation —
+/// its persisted history feeds back into the next turn — while `null` starts a
+/// fresh chat, created on the first [send] (the d-2a behaviour).
 @riverpod
 class AskController extends _$AskController {
   @override
-  AskState build() => const AskState();
+  AskState build(String? chatId) => AskState(chatId: chatId);
 
   Future<void> send(String question) async {
     final q = question.trim();

lib/features/ai/presentation/ask_screen.dart

@@ -14,9 +14,13 @@ import 'package:grabbit/features/settings/presentation/settings_controller.dart'
 /// The "Ask your library" GraphRAG chat (P13d-2a): ask a natural-language
 /// question and get a grounded, streamed answer that cites library items. Each
 /// turn re-retrieves fresh sources + a bounded slice of history. Reached from the
-/// Dashboard; generation-gated (an on-ramp routes to AI settings when no model).
+/// conversation list; generation-gated (an on-ramp routes to AI settings when no
+/// model). [chatId] continues an existing conversation (P13d-2b); `null` starts a
+/// new one, created on the first send.
 class AskScreen extends ConsumerStatefulWidget {
-  const AskScreen({super.key});
+  const AskScreen({super.key, this.chatId});
+
+  final String? chatId;
 
   @override
   ConsumerState<AskScreen> createState() => _AskScreenState();
@@ -35,7 +39,9 @@ class _AskScreenState extends ConsumerState<AskScreen> {
 
   Future<void> _onSend() async {
     final text = _input.text.trim();
-    if (text.isEmpty || ref.read(askControllerProvider).busy) return;
+    if (text.isEmpty || ref.read(askControllerProvider(widget.chatId)).busy) {
+      return;
+    }
 
     final messenger = ScaffoldMessenger.of(context);
     final router = GoRouter.of(context);
@@ -65,11 +71,22 @@ class _AskScreenState extends ConsumerState<AskScreen> {
         await router.push('/settings/ai');
       case AiSummaryAction.summarizeNow:
         _input.clear();
-        await ref.read(askControllerProvider.notifier).send(text);
+        await ref
+            .read(askControllerProvider(widget.chatId).notifier)
+            .send(text);
         _scrollToBottom();
     }
   }
 
+  /// "Ask your library" for a new chat; the (live, renamable) conversation title
+  /// when continuing an existing one.
+  String _appBarTitle(AskState state) {
+    final chatId = state.chatId;
+    if (chatId == null) return 'Ask your library';
+    return ref.watch(chatTitleProvider(chatId)).asData?.value ??
+        'Ask your library';
+  }
+
   void _scrollToBottom() {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       if (_scroll.hasClients) {
@@ -85,10 +102,10 @@ class _AskScreenState extends ConsumerState<AskScreen> {
   @override
   Widget build(BuildContext context) {
     final tokens = GrabBitTokens.of(context);
-    final state = ref.watch(askControllerProvider);
+    final state = ref.watch(askControllerProvider(widget.chatId));
 
     return Scaffold(
-      appBar: AppBar(title: const Text('Ask your library')),
+      appBar: AppBar(title: Text(_appBarTitle(state))),
       body: SafeArea(
         child: Column(
           children: [