Full internal rename: metapi → boosapi

Rename all remaining internal protocol identifiers:
- x-metapi-* headers → x-boosapi-*
- metapi: reasoning prefix → boosapi:
- __metapi* runtime markers → __boosapi*
- file-metapi-* → file-boosapi-*
- METAPI_* env vars → BOOSAPI_*
- metapi_turn_state/metapi_mcp_item__ etc. → boosapi_*
- package.json name → boosapi
- Docker/deploy/k3s/docs references

46 files changed, 168 insertions, 170 deletions.
typecheck:web passes (0 new errors).

Signed-off-by: Boos4721 <boos4721@icloud.com>

docker/docker-compose.override.yml

@@ -2,7 +2,7 @@
 # This file is automatically picked up by Docker Compose during local development.
 # It overrides the image reference in docker-compose.yml with a local build.
 services:
-  metapi:
+  boosapi:
     image: ~
     build:
       context: ..