fix(desktop): scope account access to owning client and extend identity verification

Restrict account tracking, probing, and health reporting to accounts owned
by the current client (client_id match). Extend identity-match verification
to bilibili, juejin, and smzdm so session validity is confirmed locally
rather than deferred to remote health state. Server-side account view now
uses stored client_id as authoritative owner instead of presence data.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -57,6 +57,9 @@ function createRuntimeAccountView(
     health: account.health,
     verifiedAt: account.verified_at,
   })
+  const belongsToCurrentClient = Boolean(
+    account.client_id && account.client_id === context.primaryClientId,
+  )
 
   return {
     id: account.id,
@@ -70,7 +73,7 @@ function createRuntimeAccountView(
     authReason: projected.authReason,
     tags: account.tags,
     syncVersion: account.sync_version,
-    clientId: account.client_id ?? context.primaryClientId,
+    clientId: account.client_id ?? '',
     partition: projected.partition || sessionHandle?.partition || `persist:acc-${account.id}`,
     sessionState: isHot ? 'hot' : sessionHandle ? 'warm' : 'cold',
     lastSyncAt: context.lastAccountsSyncAt || parseTimestamp(account.verified_at) || context.now,
@@ -78,7 +81,7 @@ function createRuntimeAccountView(
     lastProbeAt: projected.lastProbeAt,
     nextProbeAt: projected.nextProbeAt,
     queueDepth: accountQueueDepth,
-    online: context.clientOnline,
+    online: context.clientOnline && belongsToCurrentClient,
   }
 }