feat: add job maintenance dashboard and automated stale job expiration system

internal/db/db.go

@@ -55,7 +55,8 @@ func (db *DB) migrate() error {
 		location TEXT,
 		apply_url TEXT NOT NULL,
 		raw_content TEXT NOT NULL,
-		crawled_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		crawled_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+		last_seen_at DATETIME DEFAULT CURRENT_TIMESTAMP
 	);
 
 	CREATE TABLE IF NOT EXISTS job_analyses (
@@ -92,6 +93,37 @@ func (db *DB) migrate() error {
 	);
 	`
 
-	_, err := db.Exec(schema)
-	return err
+	if _, err := db.Exec(schema); err != nil {
+		return err
+	}
+
+	// Dynamic migration for existing databases: check if last_seen_at exists in raw_jobs
+	var hasLastSeen bool
+	rows, err := db.Query(`PRAGMA table_info(raw_jobs)`)
+	if err == nil {
+		for rows.Next() {
+			var cid int
+			var name, ctype string
+			var notnull, pk int
+			var dfltValue sql.NullString
+			if err := rows.Scan(&cid, &name, &ctype, &notnull, &dfltValue, &pk); err == nil {
+				if name == "last_seen_at" {
+					hasLastSeen = true
+					break
+				}
+			}
+		}
+		_ = rows.Close()
+	}
+
+	if !hasLastSeen {
+		if _, err := db.Exec(`ALTER TABLE raw_jobs ADD COLUMN last_seen_at DATETIME`); err != nil {
+			logger.Log.Warnw("Failed to add last_seen_at column", "component", "DB", "error", err)
+		} else {
+			_, _ = db.Exec(`UPDATE raw_jobs SET last_seen_at = crawled_at WHERE last_seen_at IS NULL`)
+			_, _ = db.Exec(`UPDATE raw_jobs SET last_seen_at = CURRENT_TIMESTAMP WHERE last_seen_at IS NULL`)
+		}
+	}
+
+	return nil
 }