fix: 防止 Worker Timeout 與改進錯誤訊息

- 加入 Oracle call_timeout (55s) 防止慢查詢阻塞 Gunicorn worker
- 改進前端 fetchWithTimeout 錯誤訊息，顯示超時的 URL
- 區分超時錯誤與網路錯誤，便於問題診斷

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

src/mes_dashboard/core/database.py

@@ -181,6 +181,7 @@ def get_db_connection():
     """Create a direct oracledb connection.
 
     Used for operations that need direct cursor access.
+    Includes call_timeout to prevent long-running queries from blocking workers.
     """
     try:
         conn = oracledb.connect(
@@ -189,7 +190,10 @@ def get_db_connection():
             retry_count=1,           # Retry once on connection failure
             retry_delay=1,           # 1s delay between retries
         )
-        logger.debug("Direct oracledb connection established")
+        # Set call timeout to 55 seconds (must be less than Gunicorn's 60s worker timeout)
+        # This prevents queries from blocking workers indefinitely
+        conn.call_timeout = 55000  # milliseconds
+        logger.debug("Direct oracledb connection established (call_timeout=55s)")
         return conn
     except Exception as exc:
         ora_code = _extract_ora_code(exc)

src/mes_dashboard/templates/wip_detail.html

@@ -764,7 +764,11 @@
 
         async function fetchWithTimeout(url, timeout = API_TIMEOUT, externalSignal = null) {
             const controller = new AbortController();
-            const timeoutId = setTimeout(() => controller.abort(), timeout);
+            let timedOut = false;
+            const timeoutId = setTimeout(() => {
+                timedOut = true;
+                controller.abort();
+            }, timeout);
 
             // If external signal is provided, abort when it fires
             if (externalSignal) {
@@ -782,9 +786,12 @@
                     if (externalSignal && externalSignal.aborted) {
                         throw error;  // Re-throw AbortError for external cancellation
                     }
-                    throw new Error('Request timeout');
+                    if (timedOut) {
+                        throw new Error(`Request timeout after ${timeout/1000}s: ${url}`);
+                    }
+                    throw error;  // Other abort (shouldn't happen, but be safe)
                 }
-                throw error;
+                throw new Error(`Network error for ${url}: ${error.message}`);
             }
         }
 

src/mes_dashboard/templates/wip_overview.html

@@ -951,7 +951,11 @@
 
         async function fetchWithTimeout(url, timeout = API_TIMEOUT, externalSignal = null) {
             const controller = new AbortController();
-            const timeoutId = setTimeout(() => controller.abort(), timeout);
+            let timedOut = false;
+            const timeoutId = setTimeout(() => {
+                timedOut = true;
+                controller.abort();
+            }, timeout);
 
             // If external signal is provided, abort when it fires
             if (externalSignal) {
@@ -969,9 +973,12 @@
                     if (externalSignal && externalSignal.aborted) {
                         throw error;  // Re-throw AbortError for external cancellation
                     }
-                    throw new Error('Request timeout');
+                    if (timedOut) {
+                        throw new Error(`Request timeout after ${timeout/1000}s: ${url}`);
+                    }
+                    throw error;  // Other abort (shouldn't happen, but be safe)
                 }
-                throw error;
+                throw new Error(`Network error for ${url}: ${error.message}`);
             }
         }