fix: Build args format for version info + schema-tolerant routes

CI/CD:
- Fix build_args format in woodpecker CI (comma-separated, not YAML list)
- This fixes "unknown" SHA/version showing on remote deployments

Backend schema-tolerant fixes (graceful fallbacks when tables missing):
- users.ts: Check which columns exist before querying
- worker-registry.ts: Return empty result if table doesn't exist
- task-service.ts: Add tableExists() helper, handle missing tables/views
- proxies.ts: Return totalProxies in test-all response

Frontend fixes:
- Proxies: Use total from response for accurate progress display
- SEO PagesTab: Dim Generate button when no AI provider active

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/services/proxyTestQueue.ts

@@ -39,7 +39,12 @@ export async function cleanupOrphanedJobs(): Promise<void> {
 
 export type ProxyTestMode = 'all' | 'failed' | 'inactive';
 
-export async function createProxyTestJob(mode: ProxyTestMode = 'all', concurrency: number = DEFAULT_CONCURRENCY): Promise<number> {
+export interface CreateJobResult {
+  jobId: number;
+  totalProxies: number;
+}
+
+export async function createProxyTestJob(mode: ProxyTestMode = 'all', concurrency: number = DEFAULT_CONCURRENCY): Promise<CreateJobResult> {
   // Check for existing running jobs first
   const existingJob = await getActiveProxyTestJob();
   if (existingJob) {
@@ -79,7 +84,7 @@ export async function createProxyTestJob(mode: ProxyTestMode = 'all', concurrenc
     console.error(`❌ Proxy test job ${jobId} failed:`, err);
   });
 
-  return jobId;
+  return { jobId, totalProxies };
 }
 
 export async function getProxyTestJob(jobId: number): Promise<ProxyTestJob | null> {