fix stuck build containers

[luke-lombardi]

Summary by cubic

Fixes stuck build and endpoint containers by requiring direct workspace storage credentials for build contexts and by preventing shutdown of containers with in‑flight requests. Also ensures containers spin up for taskless/health requests and correctly mirrors deployment active state.

• Bug Fixes

  • Builds: remove FUSE fallback for build contexts; require direct workspace storage creds; hydrate creds on build-only path via worker repo; update mount logic; add tests in pkg/worker.
  • Endpoint/Pod: skip stopping containers with consumed request tokens; generate request IDs for taskless requests; set/remove X-TASK-ID header only when a task exists; start containers for ASGI health and pod requests when none are running; remove ForwardHealthRequest; add tests in pkg/abstractions/endpoint and pkg/abstractions/pod.
  • Instance: Sync() mirrors deployment Active flag to re/activate instances; add tests in pkg/abstractions/common.

• Migration

  • Builds that use Dockerfile + BuildCtxObject now require direct workspace storage credentials. Ensure the worker can fetch workspace storage creds from the repository service or provide them directly; otherwise builds will fail with a credentials error.

^{Written for commit a7731ac. Summary will update on new commits.}