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.

plugins/ccam-dashboard/commands/open-dashboard.md

@@ -0,0 +1,35 @@
+---
+description: Print the Agent Monitor dashboard URL and how to start/open it
+---
+
+Print how to open the Claude Code Agent Monitor dashboard. Do not start anything
+or modify data — just print the URL and the relevant commands.
+
+The dashboard URL is:
+
+```
+http://localhost:4820
+```
+
+Print these in a short block:
+
+- **URL:** `http://localhost:4820`
+- **Start (production):** `npm run setup` then `npm start` from the repo root
+- **Start (dev, live reload):** `npm run dev` from the repo root
+
+Detect the platform:
+
+```bash
+uname -s
+```
+
+If the result is `Darwin` (macOS), also suggest opening it directly:
+
+```bash
+open http://localhost:4820
+```
+
+On Linux suggest `xdg-open http://localhost:4820`; otherwise just tell the user
+to open `http://localhost:4820` in a browser.
+
+Keep the output to a few lines — no preamble.