fix(daemon): honour declared SECS-II formats + make service thread-safe

Audit fixes for two real bugs in the gRPC service:

1. Format compliance: to_item() wrote F8/I8 regardless of the variable's
   declared wire format, so values contradicted the S1F11/S1F21 namelists
   (ChamberPressure is F4, WaferCounter U4; the interop trace showed <F8 2.5>
   on the wire). Conversion now targets the declared format — verified
   end-to-end: secsgem-py now receives <F4 2.5> in S6F11.

2. Thread safety: gRPC handler threads called resolve_variable/resolve_event,
   copying live store entries (including Item values) while the io thread
   mutates them. The service now snapshots the immutable name->id/format maps
   at construction (before run_async, per the documented ordering); all writes
   already post to the io thread. Remaining known narrow race (GetControlState
   enum read) documented in DAEMON_ROADMAP.

Also: drop a stale tools/run_interop.sh reference from docker-compose.yml.
Tests: daemon in-process 16/16 (new F4/U4 format assertions), core 459/459,
secsgem-py interop green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docker-compose.yml

@@ -83,8 +83,7 @@ services:
     networks: [secs]
 
   # secsgem-py running as passive equipment so the C++ active host can
-  # connect to it.  Used by tools/run_interop.sh which then launches
-  # `secs_interop_probe --host equipment_py`.
+  # connect to it (drive with `secs_interop_probe --host equipment_py`).
   equipment_py:
     build: ./interop
     volumes: