feat(execute-phase): classify quota/rate-limit failures across runtimes (#3095) (#3490)

* feat(execute-phase): classify quota/rate-limit failures across runtimes (#3095)

Dispatched executor subagents that die from provider quota or rate-limit
errors currently look identical to a crashed agent to the orchestrator —
so step 7's recovery prompt offers "retry now" when the right action is
"wait for reset and resume". This adds a runtime-agnostic classifier and
wires execute-phase step 7 to it.

- `agent.classify-failure` SDK query returns
  `{class: 'quota-exceeded' | 'classify-handoff-bug' | 'unknown-failure',
    sentinel?, retryAfterSeconds?}`. Sentinels cover Claude Code
  (`usage limit`, `429`), Copilot CLI (`rate_limit`,
  `user_weekly_rate_limited`), Codex (`usage_limit_reached`,
  `too many requests`), and Gemini (`RESOURCE_EXHAUSTED`,
  `exceeded your`).
- `execute-phase.md` step 7 now branches on the class. Quota-exceeded
  presents a wait-for-reset prompt and points at the safe-resume gate
  landing in #3212 instead of re-dispatching a fresh executor.
- `docs/research/provider-rate-limit-signals.md` records the proactive
  (header / SDK event) signals each provider exposes and the upstream
  Claude Code / Copilot / Codex issues blocking hook-side detection —
  the forward path once host runtimes surface them.

Resume-from-partial-worktree and context-load metrics from the original
report are deliberately out of scope; they overlap #3212's
`state.verify-against-disk` work already in flight.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix(execute): render quota retry hint and refresh alias artifacts

* fix(workflow): restore slash namespace and execute-phase size budget

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

sdk/src/query/command-static-catalog-foundation.ts

@@ -24,6 +24,7 @@ import { checkCompletion } from './check-completion.js';
 import { checkGates } from './check-gates.js';
 import { checkVerificationStatus } from './check-verification-status.js';
 import { checkShipReady } from './check-ship-ready.js';
+import { agentClassifyFailure } from './agent-failure-classifier.js';
 
 export const FOUNDATION_STATIC_CATALOG: ReadonlyArray<readonly [string, QueryHandler]> = [
   ['generate-slug', generateSlug],
@@ -97,4 +98,6 @@ export const DECISION_ROUTING_STATIC_CATALOG: ReadonlyArray<readonly [string, Qu
   ['check.ship-ready', checkShipReady],
   ['check ship-ready', checkShipReady],
   ['commands', commandsList],
+  ['agent.classify-failure', agentClassifyFailure],
+  ['agent classify-failure', agentClassifyFailure],
 ] as const;