Merge remote-tracking branch 'origin/master' ...

# Conflicts:
#	webclient/vendor/gnexus-ui-kit/package-lock.json

webclient: artifacts panel — compact actions, refresh in static row, file icons via phosphor 2.x ...

- artifact-actions: flex wrap gap 4px instead of full-width stretched grid
- files refresh: static toolbar row (GnIconButton sm) instead of floating
  absolute button that sat on top of the first list rows
- file icons: phosphor vendored 1.4.2 lacked the file-type glyphs
  (py/ts/js/html/css...) that fileIcon() already mapped — upgrade to
  @phosphor-icons/web 2.1.2 (bundled regular font), drop the vendor dir;
  json -> file-code (phosphor has no json glyph)

webclient: replace vue-virtual-scroller with plain content-visibility rendering ...

The virtual scroller's measurement states duplicated item views (parked
copies at translateY(-9999) alongside working ones), which made tool/plan/
thinking cards unclickable and the chat flicker. Both chat messages and
the session sidebar are now plain v-for lists; off-screen rows skip
render/paint via content-visibility: auto, keeping long sessions cheap
without the scroller engine. Library removed from dependencies.

.

security: critical batch 1 — RCE/XSS/CORS/webhook hardening ...

Backend:
- auth/deps: fix refresh-lock clock race (cleanup now monotonic like the cache)
- core/registry: add missing structlog logger (NameError on fallback path)
- config: GNAUTH_WEBHOOK_SECRET, NAVI_ALLOWED_ORIGINS (+list property)
- webhooks: HMAC-SHA256 signature verification (503 unconfigured in auth mode,
  unsigned+warning in no-auth mode, 403 bad/stale signature, 400 bad JSON)
- main: CORS from NAVI_ALLOWED_ORIGINS in auth mode (fail-fast on empty),
  eval router behind require_admin, /debug only registered in no-auth mode
- auth routes: mobile-done sid validation (32 hex) + CSP header + safe JS
  escaping (reflected XSS); Secure cookie flag via helper (https base URL)
- websocket: anonymous WS rejected in auth mode (closes legacy-session RCE);
  socket registered only after access checks; stop_session auth gate
- messages: REST agent start now takes session lock + busy flag (409 on
  active run), contextvars reset in finally

Webclient:
- useMarkdown: DOMPurify.sanitize on all rendered markdown (stored XSS),
  image-URL scheme whitelist, delegated error listener (no inline onerror)
- html.html artifact viewer: sandbox without allow-same-origin (opaque origin)
- tests: DOMPurify runs under jsdom (happy-dom Node.prototype.nodeName getter
  breaks DOMPurify); useWebSocket tests get localStorage stub + ui-kit alias

Tests: pytest 1049 passed, 1 skipped; vitest 61 passed

merge

Remove erroneous vue-router from webclient ...

vue-router was accidentally left over from an earlier attempt to embed
admin features in the main client. It broke hash-based session routing
and rendered app-main empty. Revert to direct component rendering in
App.vue with native hashchange handling.

- Remove vue-router dependency and src/router/index.js
- Revert main.js to createApp without router
- App.vue: render WelcomeScreen/ChatArea directly, restore hashchange handler
- chat.js: revert hash format to raw session id
- api/index.js: keep 401 → authStore.user = null (login overlay fix)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Fix blank session rendering and 401 auth handling ...

- Install missing vue-router dependency (was imported but not in node_modules,
  causing app init failure and empty app-main)
- Add :sessionId? route param and HomeView watcher for hash-based session routing
- Update hash format to '#/' for Vue Router compatibility
- Add 401 handling in api/index.js to invalidate auth and show login overlay
- Add error handling in loadSession and WelcomeScreen start to prevent stuck UI

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Add webclient unit tests (Vitest) — 47 tests ...

- Vitest + @vue/test-utils + happy-dom setup
- api/index.test.js: 8 tests for fetch wrapper, verbs, errors, FormData
- stores/chat.test.js: 23 tests for buildMessageList, WS handlers, load/clear
- stores/sessions.test.js: 6 tests for fetch, create, delete, pin, preview
- stores/profiles.test.js: 3 tests for fetch, auto-select, lookup
- composables/useWebSocket.test.js: 7 tests with MockWebSocket
- Export buildMessageList from chat store so tests can verify message parsing
- Update docs/testing.md with webclient stack, layout, and commands

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Migrate to Vue webclient; rename old client to old_webclient ...

- client/ → old_webclient/ (vanilla JS client preserved as reference)
- webclient/ — new Vue 3 + Pinia webclient (source + dist build)
- vite.config.js: outDir changed to webclient/dist/
- main.py: serve /assets and /images from webclient/dist/,
  index.html from webclient/dist/index.html
- .gitignore: exclude webclient/node_modules/, include webclient/dist/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>