chore: scaffold tvctl foundation

Set up the Rust crate, baseline module layout, and project docs so the
repository matches the design bundle and builds cleanly as a starting point.

docs/API.md

@@ -0,0 +1,60 @@
+# API.md
+# tvctl HTTP API Specification
+
+`tvctl` exposes a loopback-only HTTP API for tool builders at `/v1/...`.
+This file captures the v1 surface promised by the design bundle so the
+repository has a dedicated API spec from day one.
+
+## Base URL
+
+`http://127.0.0.1:7272/v1`
+
+## Response Envelope
+
+Successful responses:
+
+```json
+{ "ok": true, "data": { "...": "..." } }
+```
+
+Error responses:
+
+```json
+{
+  "ok": false,
+  "error": {
+    "code": "device_not_found",
+    "message": "No device with id 'living-room' exists.",
+    "hint": "Run tvctl device list to see known devices."
+  }
+}
+```
+
+## Planned Routes
+
+- `GET /devices`
+- `POST /devices/discover`
+- `GET /devices/{id}`
+- `DELETE /devices/{id}`
+- `GET /devices/{id}/state`
+- `GET /devices/{id}/apps`
+- `POST /devices/{id}/apps/launch`
+- `POST /devices/{id}/apps/stop`
+- `POST /devices/{id}/apps/refresh`
+- `POST /devices/{id}/remote/key`
+- `POST /devices/{id}/remote/sequence`
+- `POST /devices/{id}/dev/install`
+- `POST /devices/{id}/dev/reload`
+- `GET /devices/{id}/dev/logs`
+- `GET /daemon/status`
+- `GET /config`
+- `PATCH /config`
+- `POST /config/reload`
+
+## API Rules
+
+- All routes return the standard JSON envelope.
+- `error.code` values are stable machine contracts.
+- `error.hint` is optional but recommended for user-actionable failures.
+- Devices may be addressed by UUID or friendly name.
+- Platform-specific field names must not leak past the adapter layer.