feat(coder): complete orchestrator advanced patterns

- Approval gate steps pause and await human resolution
- appendStepEvent wired into markStep, failRun, dispatchAgentStep
- Trigger rule unit tests (6 variants)
- New parallel-research flow with one_success trigger

apps/coder/src/conductor/flows/index.ts

@@ -24,6 +24,7 @@ import {
 } from './planning.js';
 import { adr, codingStandard, runbook, tdd, stakeholderSummary } from './authoring.js';
 import { codeReview } from './code-review.js';
+import { parallelResearch } from './parallel-research.js';
 
 const spines: Spine[] = [
   // analysis / research
@@ -53,7 +54,7 @@ const spines: Spine[] = [
   stakeholderSummary,
 ];
 
-const bespoke: Flow[] = [codeReview];
+const bespoke: Flow[] = [codeReview, parallelResearch];
 
 const ALL: Flow[] = [...spines.map(buildSpineFlow), ...bespoke];