feat(service): standalone tines service with Unix-socket IPC

New `tines` crate (added to workspace members) hosting a `Node<LogStore,
BtTransport>` and serving a tiny request/response IPC over a Unix-domain
socket for robots without ROS2. Four operations: `observe`, `belief`,
`events`, and `status`, over length-prefixed JSON frames.

The `serve` loop now serves each connection request-by-request (previously
it handled one request per connection, dropping the socket after the first
response). Integration tests drive `handle`/`serve` with a mock transport
that auto-acks observed broadcasts and echoes an empty Summary, so a
confidence event fires without a real BLE radio.

Cargo.lock

@@ -1460,6 +1460,18 @@ dependencies = [
  "syn 3.0.9",
 ]
 
+[[package]]
+name = "tines"
+version = "0.3.0"
+dependencies = [
+ "heapless 0.8.0",
+ "serde",
+ "serde_json",
+ "tines-bt",
+ "tines-core",
+ "tines-store",
+]
+
 [[package]]
 name = "tines-bt"
 version = "0.3.0"