[ULis3h]

Summary

• Reserve per-agent capacity before asynchronous startup work so simultaneous runs cannot exceed maxConcurrent.
• Release reservations on startup failures, wake capacity waiters (including pending deferral logs), and clean active/running bookkeeping when dispatch throws.
• Add nine regression tests and changelog entries.

CI blockers fixed while validating

• Existing runner test glob was unsupported by Node 20. Use built-in node --test discovery, preserving all five tests.
• Docker's build stage generated Prisma for OpenSSL 1.1 while its runtime required OpenSSL 3. Install OpenSSL before build-stage npm ci so native Prisma generation matches runtime.
• Always print container logs and clean up via an EXIT trap when the Docker smoke test fails.

Validation

• Local Node 24.22.1: 67 server tests + 5 runner tests, typecheck, build, and diff checks passed.
• Previous CI verified full Node 20 and Node 22 build-and-test jobs; diagnostic Docker run confirmed the Prisma engine mismatch after successful migrations.
• Final remote tree matches local files exactly (cdc04e7089135328ef14fbe3a0133b3b53172d23). Final-head CI passed for 2b0a8fe2639ccab766b4a4b19ffc55ded94d2233: Node 20 and Node 22 typecheck/tests/build, plus Docker image build and smoke test.

No public APIs or application dependency versions changed. No merge or deployment performed.