release: v0.50.240

## Release v0.50.240

Batch release of 13 PRs that passed full triage + code review + test suite (3199 tests, 0 failures).

---

### Added

- **Compact tool activity mode** (`simplified_tool_calling`, default on) — groups tool calls and thinking traces into a single collapsed "Activity" disclosure card per assistant turn. Also adds a new **Calm Console** theme with earth/slate palette and serif prose. @Michaelyklam — #1282
- **PDF first-page preview** — `MEDIA:` `.pdf` files render a canvas thumbnail via PDF.js CDN (4 MB cap). **HTML sandbox iframe** — `.html`/`.htm` files render inline in a sandboxed `<iframe srcdoc>` (256 KB cap). 10 i18n keys × 7 locales. @bergeouss — #1280, closes #480 #482
- **Inline Excalidraw diagram preview** — `.excalidraw` files render as pure SVG (no external deps; rectangles, ellipses, diamonds, text, lines, arrows, freehand; 512 KB cap). @bergeouss — #1279, closes #479
- **Inline CSV table rendering** — fenced `csv` blocks and `MEDIA:` CSV files render as scrollable HTML tables with auto-separator detection. @bergeouss — #1277, closes #485
- **Inline SVG, audio, and video rendering** — SVG as `<img>`, audio as `<audio controls>`, video as `<video controls>`. @bergeouss — #1276, closes #481
- **Batch session select mode** — multi-select sessions for bulk Archive/Delete/Move. 11 i18n keys × 7 locales. @bergeouss — #1275, closes #568
- **Collapsible skill category headers** — click to collapse/expand without re-render; state persists across filter cycles. @bergeouss — #1281
- **`providers.only_configured` setting** — opt-in flag to restrict the model picker to explicitly configured providers. @KingBoyAndGirl — #1268
- **OpenCode Go model catalog** — adds Kimi K2.6, DeepSeek V4 Pro/Flash, MiMo V2.5/Pro, Qwen3.6/3.5 Plus. @nesquena-hermes — #1284, closes #1269

### Fixed

- **Profile `TERMINAL_CWD` TypeError** — `_build_agent_thread_env()` helper merges env before `_set_thread_env()` call. @hi-friday — #1266
- **Service worker subpath cache bypass** — regex now matches `/api/*` under any mount prefix. @Michaelyklam — #1278
- **SSE client disconnect leaks** — `TimeoutError`/`OSError` treated as clean disconnects; server backlog 64, threads daemonized; session list renders before saved-session restore. @KayZz69 — #1267
- **i18n locale corrections** — Korean MCP strings (23), Chinese MCP strings (23), zh-Hant missing keys (41), de missing keys (229). @bergeouss — #1274, closes #1273

---

### Test results

```
3199 passed, 2 skipped, 3 xpassed in 72.79s
```

### PRs on hold (not included)

#1265 (draft), #1271 (superseded by #1266), #1272 (skipped XSS tests), #1232 (partial test run), #1222 (review questions open), #1134 (live-server tests), #1132 (superseded by #1134), #1108 (negative UX review), #1084 (empty description)

server.py

@@ -24,20 +24,22 @@ from api.updates import WEBUI_VERSION
 
 class QuietHTTPServer(ThreadingHTTPServer):
     """Custom HTTP server that silently handles common network errors."""
+    daemon_threads = True
+    request_queue_size = 64
     
     def handle_error(self, request, client_address):
         """Override to suppress logging for common client disconnect errors."""
         exc_type, exc_value, _ = sys.exc_info()
         
         # Silently ignore common connection errors caused by client disconnects
-        if exc_type in (ConnectionResetError, BrokenPipeError, ConnectionAbortedError):
+        if exc_type in (ConnectionResetError, BrokenPipeError, ConnectionAbortedError, TimeoutError):
             return
         
         # Also handle socket errors that indicate client disconnect
-        if exc_type is socket.error:
+        if issubclass(exc_type, OSError):
             # errno 54 is Connection reset by peer on macOS/BSD
             # errno 104 is Connection reset by peer on Linux
-            if exc_value.errno in (54, 104, 32):  # ECONNRESET, EPIPE
+            if getattr(exc_value, 'errno', None) in (32, 54, 104, 110):  # EPIPE, ECONNRESET, ETIMEDOUT
                 return
         
         # For other errors, use default logging