fix(api): add PUT /api/settings/{key} endpoint and shared credentials for Google/Microsoft social login

- Add PUT /{key} endpoint to settings API with SettingValueUpdate body model (only
  requires value, key comes from URL path) — fixes 405 Method Not Allowed errors
  from the admin Connections wizard which used PUT to save settings
- Fix grey toggles on /admin/connections: they appeared grey because all saves were
  silently failing with 405; now saves succeed and toggles reflect actual state
- Add social_auth_google_use_global_credentials config field and auth.py logic to
  reuse google_drive_client_id/google_drive_client_secret for Google Sign-In
- Add social_auth_microsoft_use_global_credentials config field and auth.py logic to
  reuse onedrive_client_id/onedrive_client_secret for Microsoft Sign-In
- Also apply consistent both-field check for Dropbox global credentials fallback
- Add settings metadata entries for the two new boolean settings
- Add Google and Microsoft settings_keys to admin_connections service definitions
- Add JS visibility toggle logic for Google/Microsoft credential fields in admin UI
- Add 6 new unit/integration tests for PUT endpoint and SettingValueUpdate model

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/ac66041a-2cbd-4d90-8f8e-3588c629d4d8

app/api/settings.py

@@ -55,6 +55,12 @@ class SettingUpdate(BaseModel):
     value: Optional[str] = Field(None, description="Setting value (None to delete)")
 
 
+class SettingValueUpdate(BaseModel):
+    """Model for updating a setting value by key (key is provided in the URL path)."""
+
+    value: Optional[str] = Field(None, description="Setting value (None to delete)")
+
+
 class SettingResponse(BaseModel):
     """Model for setting response"""
 
@@ -323,6 +329,62 @@ async def update_setting(
         )
 
 
+@router.put("/{key}")
+async def put_setting(
+    key: str,
+    body: SettingValueUpdate,
+    request: Request,
+    db: DbSession,
+    admin: AdminUser,
+):
+    """
+    Update a specific setting by key (RESTful PUT).
+
+    Accepts a body with only ``value``; the key is taken from the URL path.
+    This is the endpoint used by the admin Connections wizard.
+    Admin only.
+    """
+    validate_setting_key(key)
+    try:
+        if body.value is not None:
+            is_valid, error_message = validate_setting_value(key, body.value)
+            if not is_valid:
+                raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=error_message)
+
+        user = request.session.get("user", {}) if hasattr(request, "session") else {}
+        changed_by = (
+            user.get("preferred_username") or user.get("username") or user.get("email") or user.get("id") or "admin"
+        )
+
+        success = save_setting_to_db(db, key, body.value, changed_by=changed_by)
+        if not success:
+            raise HTTPException(
+                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                detail="Failed to save setting to database",
+            )
+
+        notify_settings_updated()
+
+        metadata = get_setting_metadata(key)
+        restart_required = metadata.get("restart_required", False)
+
+        return {
+            "success": True,
+            "message": f"Setting '{key}' updated successfully",
+            "restart_required": restart_required,
+            "key": key,
+            "value": body.value,
+        }
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error updating setting {key}: {e}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to update setting: {key}",
+        )
+
+
 @router.delete("/{key}")
 async def delete_setting(key: str, request: Request, db: DbSession, admin: AdminUser):
     """