fix(ui): preserve server config values on partial provider config save

The submit filter in ProviderConfiguationModal only included fields where
the user had typed a new value (entry.value), causing untouched fields like
API Host to be silently dropped. Now the filter also includes fields with
existing non-masked server values (entry.serverValue), preventing config
reversion when only some fields are edited.

Fixes #7245

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: clayarnoldg2m <carnold@g2m.ai>

ui/desktop/src/components/settings/providers/modal/ProviderConfiguationModal.tsx

@@ -105,8 +105,15 @@ export default function ProviderConfigurationModal({
 
     const toSubmit = Object.fromEntries(
       Object.entries(configValues)
-        .filter(([_k, entry]) => !!entry.value)
-        .map(([k, entry]) => [k, entry.value || ''])
+        .filter(
+          ([_k, entry]) =>
+            !!entry.value ||
+            (entry.serverValue != null && typeof entry.serverValue === 'string')
+        )
+        .map(([k, entry]) => [
+          k,
+          entry.value ?? (typeof entry.serverValue === 'string' ? entry.serverValue : ''),
+        ])
     );
 
     try {