webclient: a stale session list no longer erases a session just created ...

Starting a session from the welcome screen sets selectedProfileId and
then awaits the create POST. The profile watcher fires on the microtask
that the await yields, so the list refetch is issued while the POST is
still in flight — it returns a page that predates the new session, and
fetchSessions replaced the whole array, so the placeholder createSession
had just inserted was gone. The session only came back on a manual
refresh. Reproduced in a store test.

sessions.js now remembers a session it created along with the id of the
last list request that had already started at that moment, and a page
that started after the creation is still believed. So the rescue is
bounded by one round trip — it cannot turn into a ghost row: a request
that left once the session existed reports it missing and it goes, and
deleteSession clears the mark outright. Search and special-list pages
are never padded this way, since they answer a different question.

webclient: MCP user keys panel (BYOK) + frontend tests

webclient: Synapse reactions settings + service sessions toggle ...

- 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

webclient: cap thinking body at 800px, smooth details close, Navi-viewed images grouped in artifacts ...

- thinking-body: max-height 800px + inner scroll so long reasoning
  doesn't grow the whole chat
- content-card: body stays mounted after first open (no v-show teardown
  at toggle time) — ::details-content now has real content to shrink,
  so collapsing animates smoothly instead of snapping to 0 in a frame
- synthetic '[Image loaded via ...]' messages from vision tools are no
  longer rendered as user bubbles; their images are collected (live from
  tool_call metadata, and from history) into a viewed-images group at
  the top of the artifacts tab, thumbnails open the lightbox

webclient: Backgrounds tab in artifacts panel + task toasts ...

- new Backgrounds tab: task list (running first, badges, per-tool icons)
  with a detail view (status, timestamps, sub-agent tokens, result/progress)
- GET /sessions/{id}/tasks snapshot endpoint: task_update events are not
  replayed on reconnect, so the client fetches the task list on session
  load/reload; live task_update entries are merged on top (chat.fetchTasks)
- terminal task_update no longer removes the entry — it marks it finished
  so the tab shows recent completions; _terminalTaskIds still blocks
  resurrection by a late running update
- toasts for background task start / finish (info / success / error) in
  the WS dispatch; silent for other sessions and unknown terminal ids
- persistent background-tasks chip removed (replaced by the tab); only
  the queued-messages chip stays
- fix invisible status text in terminal detail rows: filled .status-*
  backgrounds now scope to .terminal-status-badge only

background tasks: review fixes B1-B11 batch ...

- stop mid-batch cancels in-flight tools (B1) and keeps real results
  of already-finished ones, mixing them with synthetic stopped notes
  in call order (B2)
- queued messages: headless drain publishes session_sync (B4), the
  run's teardown broadcasts session_sync to other sockets but not the
  owner socket (prevents double reload) (B5)
- task_update notifications are chained per task so late running
  updates can't overtake the terminal one (B7; client drops late
  re-flicker of a terminal task chip) (B8)
- client: ui_component results reference the owning message via
  card.parentMsg instead of a stale msg reference (B6)
- tasks cancel reports the real outcome after a bounded wait instead
  of an optimistic 'cancelled' (B9)
- session delete cancels its running background jobs and drops
  pending result notes (B10)
- subagent tool loop routes background:true calls through
  ToolExecutor._maybe_background like the main loop (B11)
- tests for all of the above; docs/tasks.md stop/cancel semantics

webclient: session-list polish from review pass ...

- 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

webclient: fix session-list flicker and double-load on select ...

- 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 &/</>

webclient: loading indicators where the UI looked frozen ...

- session open: centered spinner in MessageList while chat.loading
- image paste/drop: imagesProcessing counter (chat store, shared);
  FilePreviewStrip shows spinner placeholder tiles where the resized
  previews will land
- file upload: indeterminate sliding bar instead of the fake static 60%
- send → run start gap: "Sending…" hint with spinner, cleared on
  stream_start / message_queued / stream end / error / session switch
- content-card images: skeleton with spinner until @load (reset on src
  change); wrapper keeps min-height while the img is empty

vitest 96 passed.

chat history pagination: paged load instead of full-session fetch ...

Backend:
- PgSessionStore.get_meta — light session head (sessions row + COUNT),
  no message payload
- PgSessionStore.get_history_page — page of display history (archive ∪
  hot UNION), newest-first page, oldest-first result, limit+1 peek for
  has_more; each message stamped metadata.display_index (ROW_NUMBER-1
  over the full display history) so client ids stay stable across
  paged loads; dangling-tool-call repair keeps real ranks by
  sequence-number lookup
- GET /sessions/{id}/meta and GET /sessions/{id}/messages/history
  (before_seq cursor, limit ≤200)

Webclient:
- loadSession/reloadSession fetch meta + newest 200-item page
  (Promise.all), archive state from the page itself
- buildMessageList ids (h_*) and rawIndices use the global
  display_index — feedback keys and search-jump stay stable when
  history is paged
- scroll-up loads older pages through the same history endpoint
  (archive table alone misses sessions whose threshold never moved)
- search-jump pulls pages until the target index is covered (bounded)

Tests: store unit tests (ranks, has_more peek, placeholder shift) +
vitest updates; full pytest 1231 passed, vitest 94 passed.

webclient: background task chip, id-first tool matching, queued badge ...

- toolIndex (tool_call_id → card): exact matching for parallel batches and
  late events after stream_end; legacy name+pending fallback kept
- bare tool_call synthesizes a card so results are never lost
- task_update: backgroundTasks chip above composer + steps appended to the
  spawning tool card (parent_tool_call_id binding)
- message_queued badge, terminal_opened dispatch
- new BackgroundTasksChip component, task_update step rendering in ToolCard

Add session search across messages with backend + frontend ...

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>

Paginate session list loading

Refine 3D modeler workflow

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>