feat(chinlan): port gRPC logging to a cave site

[tkgstrator]

`Hook_GrpcLogging.m` is wired only on the JB path — `Tweak.m`'s chinlan branch never calls `InstallGrpcLoggingHook`, and `recipes/kiouenginebridge.py` has no entry for the gRPC unary / streaming call sites. As a result, `[GRPC]` log lines do not appear on chinlan IPAs.

Scope

• Add the gRPC call-site RVAs to `_BRIDGE_SITES` in the recipe. Pre-orig URL + headers logging is fine as CAVE_OBSERVER; capturing the response payload would need CAVE_ENTRY (run orig via bypass, then read the reply struct).
• Wire `InstallGrpcLoggingHook(unityBase)` from the chinlan branch of `installUnityHooks` in `Sources/KiouEngineBridge/Tweak.m`.
• Bump `KIOU_BR_HOOK_` and (if any entry caves are added) `KIOU_BR_ENTRY_SLOT_` enums in `Internal.h` to match the recipe.
• Verify chinlan boot log carries `[GRPC] →[Invoker] POST …` lines once the user makes any RPC.

Acceptance

• `make CHINLAN=1` and `make FINALPACKAGE=1 FINAL_RELEASE=1 ipa` clean.
• On-device chinlan log shows the same `[GRPC]` lines a JB install emits.