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/services/flow-runner.ts

@@ -346,6 +346,20 @@ export function createFlowRunner(deps: Deps): FlowRunner {
         continue; // re-evaluate — code output can unblock the next wave
       }
 
+      // Approval gate steps: pause and wait for human decision.
+      const approvalReady = toRun.filter((s) => s.kind === 'approval');
+      if (approvalReady.length > 0) {
+        for (const s of approvalReady) {
+          await sql`
+            UPDATE flow_steps SET status = 'blocked', updated_at = clock_timestamp()
+            WHERE run_id = ${runId} AND step_id = ${s.id}
+          `;
+          await appendStepEvent(sql, runId, s.id, 'paused', { reason: 'awaiting approval' });
+          publishStep(runId, s.id, 'blocked');
+        }
+        return;
+      }
+
       // Only agent steps remain ready → dispatch the whole parallel wave, then wait.
       for (const s of toRun) {
         await dispatchAgentStep(runId, run.project_id, model, s, ctx);
@@ -393,6 +407,7 @@ export function createFlowRunner(deps: Deps): FlowRunner {
       SET task_id = ${task!.id}, status = 'running', input = ${fullPrompt}, updated_at = clock_timestamp()
       WHERE run_id = ${runId} AND step_id = ${step.id}
     `;
+    await appendStepEvent(sql, runId, step.id, 'started', { taskId: task!.id });
   }
 
   /**
@@ -439,6 +454,7 @@ export function createFlowRunner(deps: Deps): FlowRunner {
         WHERE run_id = ${runId} AND step_id = ${stepId}
       `;
     }
+    await appendStepEvent(sql, runId, stepId, status, output ? { outputLength: output.length } : undefined);
   }
 
   // ─── run completion ─────────────────────────────────────────────────────────
@@ -484,6 +500,7 @@ export function createFlowRunner(deps: Deps): FlowRunner {
     if (updated.count === 0) return;
     const stepId = failedStepId ?? (flow ? lastAgentStepId(flow, input, model) : 'run');
     log.warn({ runId, error }, 'flow-runner: run failed');
+    await appendStepEvent(sql, runId, stepId, 'failed', { error });
     publishStep(runId, stepId, 'failed', { run_status: 'failed' });
   }
 
@@ -523,7 +540,7 @@ export function createFlowRunner(deps: Deps): FlowRunner {
   function publishStep(
     runId: string,
     stepId: string,
-    status: 'running' | 'completed' | 'failed' | 'skipped' | 'cancelled',
+    status: 'running' | 'completed' | 'failed' | 'skipped' | 'cancelled' | 'blocked',
     extra?: { run_status?: 'running' | 'completed' | 'failed' | 'cancelled'; report?: string },
   ): void {
     publishUser({
@@ -765,6 +782,21 @@ function errMsg(e: unknown): string {
   return e instanceof Error ? e.message : String(e);
 }
 
+// ─── Event log ───────────────────────────────────────────────────────────────
+
+async function appendStepEvent(
+  sql: Sql,
+  runId: string,
+  stepId: string,
+  event: string,
+  payload?: Record<string, unknown>,
+): Promise<void> {
+  await sql`
+    INSERT INTO flow_step_events (run_id, step_id, event, payload)
+    VALUES (${runId}, ${stepId}, ${event}, ${payload ? sql.json(payload as never) : null})
+  `;
+}
+
 // ─── Variable substitution ───────────────────────────────────────────────────
 
 const VAR_PATTERN = /\$(\w+)\.output(?:\.(\w+(?:\.\w+)*))?/g;