feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

.claude/rules/frontend-react.md

@@ -0,0 +1,14 @@
+---
+paths:
+  - "client/src/**/*.{ts,tsx,css}"
+  - "client/public/**/*.tsx"
+---
+
+# Frontend Rules
+
+- Preserve existing UI information hierarchy unless redesign is requested.
+- Keep component props and API typing explicit; avoid implicit `any`.
+- Match existing page/component patterns for loading, empty, and error states.
+- When adding UI behavior, ensure it degrades safely if websocket updates are delayed.
+- Keep routes consistent with current navigation model.
+- Prefer focused UI diffs over broad stylistic rewrites.