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/backend-node.md

@@ -0,0 +1,14 @@
+---
+paths:
+  - "server/**/*.js"
+  - "scripts/**/*.js"
+---
+
+# Backend and Hook Rules
+
+- Keep API responses backward-compatible unless a breaking change is explicitly requested.
+- Maintain deterministic, non-blocking hook ingestion behavior.
+- Preserve transaction boundaries and data integrity in event processing logic.
+- For route changes, validate input thoroughly and return structured errors.
+- Prefer prepared-statement usage patterns already established in `server/db.js`.
+- If touching status transitions, verify session and agent lifecycle state machines still make sense.