- sidebar: service-sessions toggle (special=true fetch replaces the
  regular list, active search drops out), muted style + robot icon on
  special items in the list
- settings: Synapse reactions panel — enable switch, completion push
  preference (always / only failures / never), notification destination
  (app / app+Synapse / Synapse, Synapse options disabled while no
  source key), reaction instructions editor with save + edit history
  (author and reason per version)
- stores: synapseReactions store; sessions store fetches respect
  showSpecial; getSessions passes special param
- vitest for api/session store/panel; dist rebuilt

- documentTitle: persistent nameById map — names for sessions beyond the
  loaded list page (list only holds ~30); map filled by fetches and
  loadSession meta, never wiped by later refetches
- createSession: placeholder inserted at the position the server list
  would give it (after pinned run, last_active desc) so refetch no
  longer visibly moves the new row
- SessionItem: skip empty .session-icons wrapper when no icons
- drawer breakpoint made exclusive (-sidebar-drawer 1280 -> 1279.98):
  viewport of exactly 1280px now gets the desktop sidebar

- fetchSessions merges into existing items (preserve object references)
  instead of wholesale array replacement — DynamicScroller reuses rows,
  the list no longer repaints/reflows on every refetch (measured: sidebar
  repaint spikes 8-17% per switch -> 0)
- AppSidebar.handleSelect no longer refetches the list on a plain select;
  refetch only when leaving search (the array still held search results)
- loadSession now lives only in handleSelect — SessionList.onSelect used
  to start a first load and handleSelect raced it with a second one
  (double fetch + double buildMessageList, incl. search-jump target)
- pinSession mutates in place instead of replacing every item object
- SessionItem.highlightText matches on the raw string so <mark> offsets
  stay correct when the text contains &/</>

Backend:
- GET /sessions now accepts `search` query param
- _session_summary computes match_indices and match_preview from messages
- pg_session_store: messages ILIKE added to search_list and count_all
- In-memory store: search_list also filters by message content

Frontend:
- AppSidebar: search toggle icon + debounced input, Ctrl+K shortcut
- SessionItem: highlight matching text, show match_preview from search
- SessionList: pass searchQuery to SessionItem
- SessionsStore: searchQuery/searchActive state, setSearch/clearSearch
- API layer: getSessions accepts search param
- MessageList: scroll to target message + brightness flash animation
- ChatStore: loadSession accepts targetMessageIndex, scrollToMessageIndex ref
- CSS: msg-flash keyframe animation in app.scss
- Tests updated for new getSessions signature

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

- 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>