Adds the serve subcommand: an axum 0.7 + tower-http server on
:7700 backing the React dashboard. Routes:
GET /api/status /api/projects /api/snapshots
/api/sync-queue /api/hot /api/events (SSE 5s tick)
POST /api/activate /api/deactivate /api/sync
/api/gc /api/snapshot
Mutating endpoints shell out to /usr/local/bin/claw-store so
all CLI logic stays single-sourced. claw-store/static/ holds
the prebuilt dashboard Vite bundle for --static-dir.
cargo_init.rs gets a minor wiring tweak so the API can read
back the managed cargo config marker.
Co-Authored-By: Claude Opus 4.7 <[email protected]>