fix(ai-chat): OpenAI Chat Completions for multi-turn + provider settings, stream UX & errors" -m "Live-stand fixes (OpenRouter / OpenAI-compatible):

- openai provider: use .chat() (Chat Completions) instead of the default callable
  (Responses API), which gateways reject on multi-turn -> 400.
- updateAiProviderSettings: assemble settings.ai.provider via jsonb_build_object
  with ::text-cast bound params + jsonb_typeof self-heal (postgres.js was
  double-encoding it into an array; the ::text cast avoids 'could not determine
  data type of parameter').
- chat agent: drop the hard maxOutputTokens cap (truncated complex tool calls);
  keep a tiny cap only on the test-connection ping.
- testConnection + chat stream: surface the real provider error (statusCode+message)
  to logs and the UI instead of generic masks; never log the API key.
- chat UI: typing indicator, incremental streaming render, tool 'running' status, Stop.

Also bundled (prior uncommitted ai-chat work):
- history 'AI agent' provenance badge; vector RAG (pgvector image + page_embeddings
  + AI_QUEUE indexer + space-scoped semanticSearch); external MCP servers backend
  (@ai-sdk/mcp client, SSRF IP-pinning, encrypted headers, admin CRUD/Test);
  yjs duplicate-instance fix via pnpm patch (single CJS instance server-side).

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

@@ -52,6 +52,52 @@
     padding-inline-start: 1.4em;
 }
 
+/* Animated three-dot "typing" indicator shown while the agent is thinking but
+   has not yet produced any visible text/tool parts. */
+.typingDots {
+    display: inline-flex;
+    align-items: center;
+    gap: 4px;
+}
+
+.typingDots span {
+    width: 5px;
+    height: 5px;
+    border-radius: 50%;
+    background: var(--mantine-color-dimmed, var(--mantine-color-gray-5));
+    opacity: 0.4;
+    animation: aiTypingBounce 1.2s infinite ease-in-out;
+}
+
+.typingDots span:nth-child(2) {
+    animation-delay: 0.2s;
+}
+
+.typingDots span:nth-child(3) {
+    animation-delay: 0.4s;
+}
+
+@keyframes aiTypingBounce {
+    0%,
+    80%,
+    100% {
+        transform: translateY(0);
+        opacity: 0.4;
+    }
+    40% {
+        transform: translateY(-3px);
+        opacity: 1;
+    }
+}
+
+/* Respect reduced-motion preferences: fall back to a static dimmed state. */
+@media (prefers-reduced-motion: reduce) {
+    .typingDots span {
+        animation: none;
+        opacity: 0.6;
+    }
+}
+
 .toolCard {
     border: 1px solid light-dark(var(--mantine-color-gray-3), var(--mantine-color-dark-4));
     border-radius: var(--mantine-radius-sm);