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

client/src/components/run/LaneConsolePane.tsx

@@ -12,7 +12,8 @@
  * new lane's own live session for its slot, or an empty pane — never the
  * previous lane's terminal. `attachRequest` (a run picked in the sidebar or a
  * tab) attaches to that tmux session only; nothing is started or resumed.
- * A Claude or Codex pane also has a Chat view (`PaneChat`): the session's
+ * A pane of a `CHAT_TOOLS` tool (Claude, Codex, omp, Cursor, Antigravity) also
+ * has a Chat view (`PaneChat`): the session's
  * conversation laid OVER the terminal, which stays mounted and attached under
  * it. Chat or terminal is each SESSION's own (`useSessionChat`, the toggle
  * left of the pane's split buttons); the Chat UI setting (Settings →
@@ -29,9 +30,7 @@ import type { Lane } from "../../lib/types";
 import { useAiTools } from "../../hooks/useAiTools";
 import { TerminalView } from "./TerminalView";
 import { PaneChat } from "./PaneChat";
-import { useSessionChat } from "../../lib/chatUi";
-
-const CHAT_TOOLS = new Set(["claude", "codex"]);
+import { CHAT_TOOLS, useSessionChat } from "../../lib/chatUi";
 
 export interface LaneConsolePaneProps {
   lanes: Lane[];