refactor(worker): split god-handler into per-message type files

Extract handleWorkerMessage (380 lines, 12 positional args) into dispatcher
+ focused handler modules. Dispatcher now routes by message.type to
run-log / run-status / run-finished handlers, each receiving (event, deps,
context) triple. run-finished is further decomposed into 5 steps:
finalizeRun, accumulateAndRotateSession, emitAndNotifyCompletion,
runPostCompletionAutomation, triggerSelfWake.

No behavior change: all branches, notifications, lease renewals, circuit
breaker, and escalation semantics preserved. Schema validation stays at
dispatcher top level.

src/main/worker/handlers/run-log-handler.ts

@@ -0,0 +1,45 @@
+import { filterRunLogChunk } from "../run-log-filter";
+import { persistRunEvent } from "../run-event-recorder";
+import type { HandlerContext, HandlerDeps, WorkerMessageEvent } from "./handler-context";
+
+const LEASE_RENEWAL_INTERVAL_MS = 5 * 60 * 1000; // 5 minutes
+
+export async function handleRunLog(
+  event: Extract<WorkerMessageEvent, { type: "run-log" }>,
+  deps: HandlerDeps,
+  context: HandlerContext,
+): Promise<void> {
+  const { db, logger, emitEvent } = deps;
+  const { leaseRenewalMap } = context;
+
+  const filtered = filterRunLogChunk(event.stream, event.chunk);
+  if (filtered === null) return;
+
+  await db.appendRunLog(event.runId, event.stream, filtered);
+  const runState = db.getRunAuthState(event.runId);
+  if (runState) {
+    persistRunEvent(db, logger, {
+      companyId: runState.companyId,
+      runId: event.runId,
+      agentId: runState.agentId,
+      eventType: "run_log",
+      stream: event.stream,
+      message: filtered,
+    });
+  }
+  emitEvent({ ...event, chunk: filtered });
+
+  // Throttled lease renewal: keep execution lock alive for long-running tasks.
+  // Without this, tasks exceeding the 15-minute stale lock timeout get reclaimed.
+  const now = Date.now();
+  const lastRenewal = leaseRenewalMap.get(event.runId) ?? 0;
+  if (now - lastRenewal >= LEASE_RENEWAL_INTERVAL_MS) {
+    try {
+      const run = db.getRun(event.runId);
+      db.renewTaskLease(run.taskId, run.id);
+      leaseRenewalMap.set(event.runId, now);
+    } catch {
+      // Run not found — skip lease renewal
+    }
+  }
+}