fix: end buffer if exception occurs in page (#50)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Improved reliability when loading the Tailscale plugin page by adding
robust error handling.
* Prevents partial or corrupted page output if an error occurs during
content rendering.
* Ensures the page cleans up correctly on failures and returns
consistent content on success.
* No changes to visible functionality; enhances stability and user
experience.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: Derek Kaser <[email protected]>

Author: dkaser

src/usr/local/emhttp/plugins/tailscale/include/page.php

@@ -46,8 +46,13 @@ function includePage(string $filename, array $params = array()): string
 
     if (is_file($filename)) {
         ob_start();
-        include $filename;
-        return ob_get_clean() ?: "";
+        try {
+            include $filename;
+            return ob_get_clean() ?: "";
+        } catch (\Throwable $e) {
+            ob_end_clean();
+            throw $e;
+        }
     }
     return "";
 }