batch4: chats-in-sessions, force-send, /compact, right-rail file browser

Session 1:N Chat data model with backfill. Workspace switches to client-side
multi-tab pane management. Right-rail file browser with float-over viewer and
click-drag line selection replaces FileBrowserPane. Adds /compact streaming
summarizer (respects compact markers in context builder), force-send (cancels
in-flight, persists partial as 'cancelled', awaits cancellation completion via
deferred Promise + 5s timeout), message queue, stop generation, chat
auto-rename, session archive/unarchive with Closed Sessions section on repo
landing page. CHECK constraints on sessions.status, messages.role,
messages.status with KEEP IN SYNC comments tying to MESSAGE_ROLES /
MESSAGE_STATUSES const arrays. Deletes dead pane routes/hook and the
api.panes.* client block.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/api/client.ts

@@ -2,14 +2,12 @@ import type {
   Project,
   AvailableProject,
   Session,
+  Chat,
   Message,
   ModelInfo,
   SidebarResponse,
   ListDirResult,
   ViewFileResult,
-  Pane,
-  PaneCreateRequest,
-  PaneUpdateRequest,
 } from './types';
 
 export class ApiError extends Error {
@@ -61,8 +59,8 @@ export const api = {
   },
 
   sessions: {
-    listForProject: (projectId: string) =>
-      request<Session[]>(`/api/projects/${projectId}/sessions`),
+    listForProject: (projectId: string, status?: 'open' | 'archived') =>
+      request<Session[]>(`/api/projects/${projectId}/sessions${status ? `?status=${status}` : ''}`),
     create: (
       projectId: string,
       body: { name?: string; model?: string; system_prompt?: string }
@@ -82,22 +80,54 @@ export const api = {
       }),
     remove: (id: string) =>
       request<void>(`/api/sessions/${id}`, { method: 'DELETE' }),
+    archive: (id: string) =>
+      request<void>(`/api/sessions/${id}/archive`, { method: 'POST' }),
+    unarchive: (id: string) =>
+      request<Session>(`/api/sessions/${id}/unarchive`, { method: 'POST' }),
+  },
+
+  chats: {
+    listForSession: (sessionId: string) =>
+      request<Chat[]>(`/api/sessions/${sessionId}/chats`),
+    create: (sessionId: string, body?: { name?: string }) =>
+      request<Chat>(`/api/sessions/${sessionId}/chats`, {
+        method: 'POST',
+        body: JSON.stringify(body ?? {}),
+      }),
+    update: (chatId: string, body: { name?: string; status?: 'open' | 'closed' }) =>
+      request<Chat>(`/api/chats/${chatId}`, {
+        method: 'PATCH',
+        body: JSON.stringify(body),
+      }),
+    remove: (chatId: string) =>
+      request<void>(`/api/chats/${chatId}`, { method: 'DELETE' }),
+    messages: (chatId: string) =>
+      request<Message[]>(`/api/chats/${chatId}/messages`),
+    compact: (chatId: string) =>
+      request<{ compact_message_id: string }>(`/api/chats/${chatId}/compact`, { method: 'POST' }),
+    stop: (chatId: string) =>
+      request<{ stopped: boolean }>(`/api/chats/${chatId}/stop`, { method: 'POST' }),
+    forceSend: (chatId: string, content: string) =>
+      request<{ user_message_id: string; assistant_message_id: string }>(
+        `/api/chats/${chatId}/force_send`,
+        { method: 'POST', body: JSON.stringify({ content }) }
+      ),
   },
 
   messages: {
     list: (sessionId: string) =>
       request<Message[]>(`/api/sessions/${sessionId}/messages`),
-    send: (sessionId: string, content: string) =>
+    send: (chatId: string, content: string) =>
       request<{ user_message_id: string; assistant_message_id: string }>(
-        `/api/sessions/${sessionId}/messages`,
+        `/api/chats/${chatId}/messages`,
         {
           method: 'POST',
           body: JSON.stringify({ content }),
         }
       ),
-    regenerate: (sessionId: string, messageId: string) =>
+    regenerate: (chatId: string, messageId: string) =>
       request<{ assistant_message_id: string }>(
-        `/api/sessions/${sessionId}/messages/${messageId}/regenerate`,
+        `/api/chats/${chatId}/messages/${messageId}/regenerate`,
         { method: 'POST' }
       ),
   },
@@ -116,21 +146,4 @@ export const api = {
   sidebar: {
     get: () => request<SidebarResponse>('/api/sidebar'),
   },
-
-  panes: {
-    getForSession: (sessionId: string) =>
-      request<{ panes: Pane[] }>(`/api/sessions/${sessionId}/panes`),
-    create: (sessionId: string, body: PaneCreateRequest) =>
-      request<Pane>(`/api/sessions/${sessionId}/panes`, {
-        method: 'POST',
-        body: JSON.stringify(body),
-      }),
-    update: (id: string, body: PaneUpdateRequest) =>
-      request<Pane>(`/api/panes/${id}`, {
-        method: 'PATCH',
-        body: JSON.stringify(body),
-      }),
-    remove: (id: string) =>
-      request<void>(`/api/panes/${id}`, { method: 'DELETE' }),
-  },
 };