sightsound: move FLM NPU endpoint port 52626 -> 7771

Env file is the source of truth (unit ExecStart runs the serve script which
sources it); serve-script default and the deployer health-gate URL flipped in
lockstep so the post-restart health gate polls the new port. Docs, fleet table,
and both index bullets updated to match.

scripts/frank-default-sightsound.env

@@ -9,7 +9,7 @@
 # available there at idle, so a 9.1 GB pack fits with headroom.
 FLM_MODEL=gemma4-it:e4b
 FLM_HOST=0.0.0.0
-FLM_PORT=52626
+FLM_PORT=7771
 # turbo = max NPU power mode (xrt-smi configure --pmode turbo at serve start).
 # No other tenant uses the NPU on this host, so the top mode costs nothing to
 # neighbours; drop to `performance` if iGPU power-budget contention ever shows.