docs: clarify bridge upgrade for coworkers

docs/internal-extension-distribution.md

@@ -76,6 +76,20 @@ The pipeline uses the tag as the release version. Recommended format: `0.MMDD.N`
 5. Select the unzipped `dist/` folder.
 6. Confirm the extension ID is `pkjopdibdnomhogjheclhnknmejccffg`.
 
+## One-Time Bridge Upgrade
+
+Some coworkers may still be using an older unpacked build whose popup cannot read the COS update manifest and only shows:
+
+- `暂时无法检查更新`
+
+For those users, ask them to do one manual bridge upgrade with the newest ZIP:
+
+1. Download the newest `star-chart-search-enhancer-internal.zip`.
+2. Unzip it and get the new `dist/` folder.
+3. Re-load that `dist/` folder in `chrome://extensions`.
+
+After this one-time bridge upgrade, future updates should continue using the same `dist/` layout.
+
 ## Notes
 
 - Keep `.local/extension-key.pem` private and backed up internally.