feat: ship HTTP dashboard and harden daemon/API flows

Add the static HTTP dashboard example and wire in the recent daemon/API polish:
CORS-aware API routing, service-install behavior cleanup, safer systemd unit
ExecStart quoting, and friendly-name validation for path-safe targeting.

Also refresh README/API/roadmap docs, remove the temporary claude observations
file, and include the related tests for API/status and daemon validation.

PROJECT_MAP.md

@@ -42,6 +42,8 @@ tvctl/
 │   ├── DESIGN.md           ← Full design decisions and rationale
 │   ├── API.md              ← HTTP API specification (detailed)
 │   └── ADAPTER.md          ← Adapter trait spec and implementation guide
+├── examples/
+│   └── http-dashboard/     ← Static browser dashboard for /v1 API endpoint testing
 ├── src/
 │   ├── lib.rs              ← Library surface for shared modules and integration tests
 │   ├── main.rs             ← Binary entry point and runtime bootstrap