feat(ai-chat): agent write tools, provenance wiring, chat panel + provider settings UI" -m "Backend:

- Add reversible write tools to the per-user agent toolset (page create/update/
  move/soft-delete; comment reply + resolve), exposed under the user's JWT and
  enforced by Docmost CASL; no permanent/force delete (D3).
- Non-spoofable agent provenance: sign actor/aiChatId into the access and collab
  tokens (TokenService), propagate via jwt.strategy onto the request, and set
  pages.last_updated_source/last_updated_ai_chat_id on REST create/update/move and
  comments.created_source/resolved_source/ai_chat_id.
- packages/mcp: add an optional getCollabToken provider (content-edit provenance)
  and guard against empty tokens; service-account /mcp path unchanged.

Frontend:
- Admin 'AI / Models' settings section: provider/model/embedding/base URL, a
  write-only API key field, system prompt, and Test connection.
- AI chat panel (useChat + DefaultChatTransport): conversation list, streamed
  messages, tool-call action log and page citations; header entry point gated on
  settings.ai.chat.

Compile-verified (server nest build + client tsc/vite); not yet live-tested.
Known gaps: history 'AI agent' badge (C3), vector RAG (D), external MCP (E);
chat tool-card citation links pending a fix.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/ai-chat/components/ai-chat.module.css

@@ -0,0 +1,79 @@
+.panel {
+    display: flex;
+    flex-direction: column;
+    height: 100%;
+    min-height: 0;
+}
+
+.messages {
+    flex: 1 1 auto;
+    min-height: 0;
+}
+
+.messageRow {
+    margin-bottom: var(--mantine-spacing-md);
+}
+
+.userBubble {
+    background: var(--mantine-color-gray-light);
+    border-radius: var(--mantine-radius-md);
+    padding: 8px 12px;
+    white-space: pre-wrap;
+    overflow-wrap: break-word;
+    word-break: break-word;
+}
+
+/* Rendered markdown for assistant messages. Keep block margins compact. */
+.markdown {
+    overflow-wrap: break-word;
+    word-break: break-word;
+}
+
+.markdown p {
+    margin-block-start: 0;
+    margin-block-end: 0.5em;
+}
+
+.markdown pre {
+    background: var(--mantine-color-gray-light);
+    border-radius: var(--mantine-radius-sm);
+    padding: 8px;
+    overflow-x: auto;
+}
+
+.markdown code {
+    font-size: 0.85em;
+}
+
+.markdown ul,
+.markdown ol {
+    margin-block-start: 0;
+    margin-block-end: 0.5em;
+    padding-inline-start: 1.4em;
+}
+
+.toolCard {
+    border: 1px solid light-dark(var(--mantine-color-gray-3), var(--mantine-color-dark-4));
+    border-radius: var(--mantine-radius-sm);
+    padding: 6px 10px;
+    margin-bottom: 6px;
+    background: light-dark(var(--mantine-color-gray-0), var(--mantine-color-dark-6));
+}
+
+.inputWrapper {
+    flex: 0 0 auto;
+    padding-top: var(--mantine-spacing-xs);
+}
+
+.conversationItem {
+    cursor: pointer;
+    border-radius: var(--mantine-radius-sm);
+}
+
+.conversationItem:hover {
+    background: var(--mantine-color-gray-light);
+}
+
+.conversationItemActive {
+    background: var(--mantine-color-gray-light);
+}