feat(chat): terminal chat parity for every tool; Desktop-like artifacts

- The chat over a terminal pane now covers Claude, Codex, omp, Cursor and
  Antigravity: Cursor's agent transcript and agy's step log
  (brain/<id>/.system_generated/logs/transcript_full.jsonl) are read as
  conversations; Cursor sessions are claimed by their workspace
- Replies appear as soon as they are written: the projects-tree watcher
  broadcasts `transcript_changed` (at most every 250 ms per session) and the
  chat re-reads the transcript while the terminal underneath draws
- Stop shows from the pane's own busy line (Claude/Codex `esc to interrupt`,
  agy `… esc to cancel`), or fresh output for omp/Cursor — no hooks needed
- Permission prompts read off the terminal become a card with the tool, its
  command and "Deny with a note"; Codex gets Permission mode / Model buttons
  that open its own numbered pickers, answered from the menu card
- Artifacts: cards for pages/documents/diagrams/tables/React components, a
  Preview | Code panel with versions, copy, download, save to the Artifacts
  Hub, full screen; sandboxed iframes without allow-same-origin
- Claude panes get CLAUDE_CODE_ENABLE_TODO_TOOLS=1 so the Progress panel has a
  plan; multi-question pane menus read their Next row and question tabs
- The realtime chat bridge (structured stdio, /api/chat-bridge, /ws-chat)
  from the unreleased ad9d475 is not kept

server/README.md

@@ -632,12 +632,19 @@ An `antigravity` workspace carries no pipeline either.
   per-conversation SQLite files (`~/.gemini/antigravity-cli/conversations/<id>.db`)
   every `DASHBOARD_ANTIGRAVITY_POLL_MS` ms (default 15000, `0` disables). They
   become `sessions` rows (`tool = 'antigravity'`) and `token_usage` rows, and
-  `antigravity_conversations` holds the mtime read for each file.
+  `antigravity_conversations` holds the mtime read for each file. The
+  session's conversation (`GET /api/sessions/:id/transcript`) is read from its
+  step log (`brain/<id>/.system_generated/logs/transcript_full.jsonl`,
+  `transcriptPath`): prompts, the model's text, thinking, tool calls and
+  tokens, and each tool's result tied to its call by step.
 - **Cursor sessions:** `server/lib/cursor-usage.js` reads Cursor's agent
   transcripts (`~/.cursor/projects/*/agent-transcripts/<id>/<id>.jsonl`) every
   `DASHBOARD_CURSOR_POLL_MS` ms (default 15000, `0` disables) into `sessions`
   rows (`tool = 'cursor'`) — no `token_usage`, the transcripts carry none —
-  and `cursor_transcripts` holds the mtime read for each file.
+  and `cursor_transcripts` holds the mtime read for each file. The session's
+  conversation (`GET /api/sessions/:id/transcript`) is read from that recorded
+  file: prompts, replies, thinking, tool calls and results, with no timestamps
+  or model (Cursor writes none).
 - **Oh My Pi sessions:** `server/lib/omp-usage.js` reads omp's session journals
   (`~/.omp/agent/sessions/<encoded cwd>/<timestamp>_<id>.jsonl`, plus every
   subagent journal under `<timestamp>_<id>/`) every `DASHBOARD_OMP_POLL_MS` ms
@@ -803,7 +810,7 @@ HTTP surface for the tmux-backed terminal run: one session per workspace, named
 
 Codex-only spawn options (`sandbox`, `approval`, `resumeLast`) are accepted by the workspace action `POST /api/lanes/:id/start`, not by `POST /api/run` — see [`docs/API.md`](../docs/API.md).
 
-The pane itself is not JSON: its bytes stream over `/ws-pty/:runId` as binary WebSocket frames. The JSON WebSocket surface adds `cc_config_changed` (broadcast by `lib/cc-watcher.js` on `fs.watch` events under `~/.claude/` and by `routes/cc-config.js` after every successful PUT/DELETE — debounced at 500 ms, payload `{ source: "dashboard"|"fs", action?, scope?, type?, name?, paths? }`) and its Codex counterpart `codex_config_changed` (broadcast by `routes/codex-config.js` after every successful file mutation and CLI-backed mcp/plugin/marketplace action — always `source: "dashboard"`, there is no `$CODEX_HOME` filesystem watcher).
+The pane itself is not JSON: its bytes stream over `/ws-pty/:runId` as binary WebSocket frames. The JSON WebSocket surface adds `cc_config_changed` (broadcast by `lib/cc-watcher.js` on `fs.watch` events under `~/.claude/` and by `routes/cc-config.js` after every successful PUT/DELETE — debounced at 500 ms, payload `{ source: "dashboard"|"fs", action?, scope?, type?, name?, paths? }`) and its Codex counterpart `codex_config_changed` (broadcast by `routes/codex-config.js` after every successful file mutation and CLI-backed mcp/plugin/marketplace action — always `source: "dashboard"`, there is no `$CODEX_HOME` filesystem watcher), and `transcript_changed` `{ session_id }` — the session sync's `fs.watch` on the projects tree saw a Claude transcript grow (`pushTranscript` in `server/index.js`, at most every 250 ms per session; nothing is parsed for it), so a chat showing that session reads its new lines at once instead of at its next 3 s poll. It reaches whoever the session's own `new_event` reaches (`broadcastAudience`).
 
 ### Import History