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.

desktop/.gitignore

@@ -0,0 +1,10 @@
+node_modules/
+out/
+release/
+*.log
+.DS_Store
+
+# Generated icon binaries — regenerable from assets/icon.svg via scripts/build-icons.sh.
+# Committed copies live alongside the SVG so users without iconutil can still build.
+# Local rebuilds are ignored.
+assets/icon.iconset/