feat(desktop): add monitor scheduler, Playwright CDP layer, and account health

Move monitor-task scheduling authority onto the client with a durable
file-backed queue that survives restart, drops stale cross-day tasks,
enforces per-platform serialism, and adapts global concurrency from
Electron process metrics. Publish tasks keep their existing FIFO.

Add a hidden Playwright CDP manager that attaches to Electron Chromium
on account session partitions, lets adapters opt into `executionMode:
"playwright"`, and leaves the existing hidden WebContentsView path in
place for current adapters.

Introduce an account-health subsystem with silent probes, projected
health/auth states, and IPC invalidation events so the renderer can
show accurate auth/probe status and verification timestamps.

Server-side, derive and forward title/business_date/scheduler_group_key/
question_text metadata on desktop task events so the local scheduler
can defer same-question fan-out before leasing.

apps/desktop-client/src/main/runtime-snapshot.ts

@@ -1,10 +1,13 @@
 import { app } from "electron/main";
 
+import { getProjectedAccountHealth } from "./account-health";
 import { getProcessMetricsSnapshot } from "./process-metrics";
 import { getCircuitBreakerState } from "./circuit-breaker";
 import { collectRecoverySnapshot } from "./crash-recovery";
 import { getKeepAlivePlan } from "./keep-alive";
 import { getLeaseManagerSnapshot } from "./lease-manager";
+import { getMonitorSchedulerSnapshot } from "./monitor-scheduler";
+import { getHiddenPlaywrightSnapshot } from "./playwright-cdp";
 import { getRateLimiterSnapshot } from "./rate-limiter";
 import { getRuntimeControllerSnapshot } from "./runtime-controller";
 import { getSchedulerState } from "./scheduler";
@@ -71,23 +74,35 @@ function createLiveRuntimeSnapshot(controller: ReturnType<typeof getRuntimeContr
     const accountQueueDepth = controller.tasks.filter((task) =>
       task.accountId === account.id && ["queued", "in_progress"].includes(task.status),
     ).length;
+    const projected = getProjectedAccountHealth({
+      accountId: account.id,
+      platform: account.platform,
+      health: account.health,
+      verifiedAt: account.verified_at,
+    });
 
     return {
       id: account.id,
       platform: account.platform,
-      displayName: account.display_name,
+      displayName: projected.profile?.displayName ?? account.display_name,
       platformUid: normalizeAccountPlatformUid(account.platform_uid) || account.platform_uid,
-      avatarUrl: account.avatar_url ?? null,
-      health: account.health,
+      avatarUrl: projected.profile?.avatarUrl ?? account.avatar_url ?? null,
+      health: projected.health,
+      authState: projected.authState,
+      probeState: projected.probeState,
+      authReason: projected.authReason,
       tags: account.tags,
       syncVersion: account.sync_version,
       clientId: account.client_id ?? primaryClientId,
-      partition: sessionHandle?.partition ?? `persist:acc-${account.id}`,
+      partition: projected.partition || sessionHandle?.partition || `persist:acc-${account.id}`,
       sessionState: isHot ? "hot" : sessionHandle ? "warm" : "cold",
       lastSyncAt:
         controller.lastAccountsSyncAt
         || parseTimestamp(account.verified_at)
         || now,
+      lastVerifiedAt: projected.lastVerifiedAt,
+      lastProbeAt: projected.lastProbeAt,
+      nextProbeAt: projected.nextProbeAt,
       queueDepth: accountQueueDepth,
       online: clientOnline,
     };
@@ -150,9 +165,11 @@ function createLiveRuntimeSnapshot(controller: ReturnType<typeof getRuntimeContr
         lastError: controller.lastError,
       },
       scheduler,
+      monitorScheduler: getMonitorSchedulerSnapshot(),
       sessions,
       hotViews,
       hotViewPool: getHotViewPoolPolicy(),
+      playwright: getHiddenPlaywrightSnapshot(),
       processMetrics: getProcessMetricsSnapshot(),
       vault: describeVaultBackend(),
     },