v0.50.25: mobile scroll, import timestamps, profile security, mic fallback (#404)

* fix: restore mobile chat scrolling and drawer close (#397)

- static/style.css: add min-height:0 to .layout and .main (flex shrink chain fix for mobile scroll)
- static/style.css: add -webkit-overflow-scrolling:touch, touch-action:pan-y, overscroll-behavior-y:contain to .messages
- static/boot.js: call closeMobileSidebar() on new-conversation button onclick and Ctrl+K shortcut
- tests/test_mobile_layout.py: 41 new lines covering all three CSS fixes and both JS call sites

Original PR by @Jordan-SkyLF

* fix: preserve imported session timestamps (#395)

- api/models.py: add touch_updated_at: bool = True param to Session.save(); import_cli_session() accepts created_at/updated_at kwargs and saves with touch_updated_at=False
- api/routes.py: extract created_at/updated_at from get_cli_sessions() metadata and forward to import_cli_session(); use touch_updated_at=False on post-import save
- tests/test_gateway_sync.py: +53 lines — integration test verifying imported session keeps original timestamp and sorts correctly vs newer sessions; also fix: add WebUI session file cleanup in finally block

Original PR by @Jordan-SkyLF

* fix(profiles): block path traversal in profile switch and delete flows (#399)

Master was vulnerable: switch_profile and delete_profile_api joined user-supplied profile
names directly into filesystem paths with no validation. An attacker could send
'../../etc/passwd' as a profile name to traverse outside the profiles directory.

- api/profiles.py: add _resolve_named_profile_home(name) — validates name with
  ^[a-z0-9][a-z0-9_-]{0,63}$ regex then enforces path containment via
  candidate.resolve().relative_to(profiles_root); use in switch_profile()
- api/profiles.py: add _validate_profile_name() call to delete_profile_api() entry
- api/routes.py: add _validate_profile_name() call at HTTP handler level for
  both /api/profile/switch and /api/profile/delete (fail-fast at API boundary)
- tests/test_profile_path_security.py: 3 tests — traversal rejected, valid name passes

Cherry-picked commit aae7a30 from @Hinotoi-agent (PR was 62 commits behind master)

* feat: add desktop microphone transcription fallback (#396)

Mic button now works in browsers that support getUserMedia/MediaRecorder but
lack SpeechRecognition (e.g. Firefox desktop, some Chromium builds).

- static/boot.js: detect _canRecordAudio (navigator.mediaDevices + getUserMedia + MediaRecorder);
  keep mic button enabled when either SpeechRecognition or MediaRecorder is available;
  MediaRecorder fallback records audio, sends blob to /api/transcribe, inserts transcript
  into the composer; _stopMic() handles all three states (recognition, mediaRecorder, neither)
- api/upload.py: add transcribe_audio() helper — saves uploaded blob to temp file, calls
  transcription_tools.transcribe_audio(), always cleans up temp file
- api/routes.py: add /api/transcribe POST handler — CSRF protected, auth-gated, 20MB limit,
  returns {text:...} or {error:...}
- api/helpers.py: change Permissions-Policy microphone=() to microphone=(self) (required to
  allow getUserMedia in the same origin)
- tests/test_voice_transcribe_endpoint.py: 87 new lines — 3 tests with mocked transcription
- tests/test_sprint19.py: +1 regression guard (microphone=(self) in Permissions-Policy)
- tests/test_sprint20.py: 3 updated tests for new fallback-capability checks

Original PR by @Jordan-SkyLF

* docs: v0.50.25 release — version badge and CHANGELOG

---------

Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>

tests/test_sprint19.py

@@ -80,6 +80,16 @@ def test_security_headers_on_health():
     assert headers.get("X-Content-Type-Options") == "nosniff"
 
 
+def test_permissions_policy_does_not_disable_microphone():
+    """Permissions-Policy must not hard-disable microphone access for same-origin voice input."""
+    _, status, headers = get("/health")
+    assert status == 200
+    policy = headers.get("Permissions-Policy", "")
+    assert policy, "Permissions-Policy header missing"
+    assert "microphone=()" not in policy, \
+        "Permissions-Policy must not block microphone access or desktop/mobile voice input cannot work"
+
+
 def test_cache_control_no_store():
     """API responses should have Cache-Control: no-store."""
     d, status, headers = get("/api/sessions")