feat(contracts,db): agent.plan / agent.propose_options, interaction events, proposeFirst replaces run mode

- agent_run_event gains plan_updated, options_proposed/resolved, approval_requested/resolved (migration 0040)
- AgentRunStartInput.proposeFirst; mode deprecated (plan_only maps to proposeFirst); mode dropped from AgentRun API
- POST /agent/runs/{id}/choice; agent.optionsTimeoutSec/optionsTimeoutAction/approvalTimeoutSec settings

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/contracts/test/schemas.test.ts

@@ -103,6 +103,11 @@ const OVERRIDES: Record<string, (v: Record<string, unknown>) => Record<string, u
   ReleaseIdentityAssign: (v) => ({ ...v, external: undefined, candidateIndex: undefined }),
   CacheSettings: (v) => ({ ...v, hardThresholdPercent: 90, resumePercent: 85, cleanupTargetPercent: 80 }),
   GlobalSettings: () => C.DEFAULT_SETTINGS,
+  // 方案至少 2 个(id 不同)
+  AgentProposeOptionsInput: (v) => {
+    const o = (v.options as Record<string, unknown>[])[0]!;
+    return { ...v, options: [o, { ...o, id: "b" }] };
+  },
   EngineStats: (v) => ({ ...v, byStatus: { pending: 1 } }),
   TypedEventEnvelope: () => ({
     seq: 1,