refactor: centralize run status and simplify runtime ownership

[mewcoder]

Why

Run status had several secondary write paths and failure windows, while Runtime Host lifecycle state still exposed lower-level mutation APIs. That made Run/Conversation projection convergence and worker cleanup harder to reason about.

What

The original refactor remains intact, including the registered Runtime Host execution chain. This follow-up adds thirteen isolated commits:

1. fix(runtime): keep dependency sync build-free
   • read bundled plugin IDs from a pure manifest so dependency verification does not import unbuilt agent packages
2. refactor(run): route launch failures through status owner
   • send runtime submit failures through RunStatusService
3. refactor(run): converge stale cancellation centrally
   • route no-handle cancellation through the same Run/Conversation/SSE transition owner
4. fix(run): release failed launch claims
   • reconcile a claimed Conversation when message or Run creation fails, without overwriting a newer active run
5. test(run): guard status ownership boundaries
   • prevent new production writes outside RunStatusService
6. fix(run): reconcile stale conversation projections
   • repair Conversation projections left running after restart when no active Run exists
7. refactor(runtime): encapsulate worker pool lifecycle
   • use composition so RuntimeHost cannot bypass registry eviction with raw WorkerPool.remove
8. chore: align run refactor quality gates
   • normalize formatting and satisfy lint rules
9. fix(ci): satisfy server lint gates
   • clear the original PR's deferred server lint failures exposed after runtime typecheck was fixed
10. fix(test): validate runtime plugin identifiers
    • align the stale closed-enum DTO test with the open runtime plugin identifier contract
11. fix(run): guard conversation projection ownership
    • add Conversation.activeRunId compare-and-set ownership so an older Run cannot overwrite a newer Run's Conversation projection during steering
12. fix(test): align conversation projection mock
    • update the Runtime Host upstream test double for the new Conversation projection port
13. fix(test): satisfy run status lint
    • remove an unused test binding caught by the full lint gate

The registered execution/tunnel chain is preserved.

Validation

GitHub Actions Server workflow #44 passed:

• adapters TypeScript: pass
• runtime TypeScript: pass
• server TypeScript: pass
• server ESLint/Prettier: pass
• adapters full suite: 14 files, 216 tests pass
• runtime full suite: 24 files, 227 tests pass
• server full suite: 92 files, 806 tests pass