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>

src/web/i18n.supplement.ts

@@ -259,7 +259,7 @@ export const zhToEnSupplemental: Record<string, string> = {
   '拉取分组失败': 'Failed to pull group',
   '拉取分组失败，已回退 default': 'Failed to pull the group and has fallen back to default',
   '冷却中': 'Cooling down',
-  '例如 BoosAPI': 'For example metapi',
+  '例如 BoosAPI': 'For example BoosAPI',
   '例如: admin@example.com': 'For example: admin@example.com',
   '例如: smtp.qq.com': 'For example: smtp.qq.com',
   '例如: target@example.com': 'For example: target@example.com',