feat(plugins): add JSONForms-based plugin configuration UI (#4911)

* feat(plugins): add JSONForms schema for plugin configuration

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enhance error handling by formatting validation errors with field names

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enforce required fields in config validation and improve error handling

Signed-off-by: Deluan <deluan@navidrome.org>

* format JS code

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add config schema validation and enhance manifest structure

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: refactor plugin config parsing and add unit tests

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add config validation error message in Portuguese

* feat: enhance AlwaysExpandedArrayLayout with description support and improve array control testing

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: update Discord Rust plugin configuration to use JSONForm for user tokens and enhance schema validation

Signed-off-by: Deluan <deluan@navidrome.org>

* fix: resolve React Hooks linting issues in plugin UI components

* Apply suggestions from code review

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* format code

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: migrate schema validation to use santhosh-tekuri/jsonschema and improve error formatting

Signed-off-by: Deluan <deluan@navidrome.org>

* address PR comments

Signed-off-by: Deluan <deluan@navidrome.org>

* fix flaky test

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enhance array layout and configuration handling with AJV defaults

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: implement custom tester to exclude enum arrays from AlwaysExpandedArrayLayout

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add error boundary for schema rendering and improve error messages

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: refine non-enum array control logic by utilizing JSONForms schema resolution

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add error styling to ToggleEnabledSwitch for disabled state

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: adjust label positioning and styling in SchemaConfigEditor for improved layout

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: implement outlined input controls renderers to replace custom fragile CSS

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: remove margin from last form control inside array items for better spacing

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enhance AJV error handling to transform required errors for field-level validation

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: set default value for User Tokens in manifest.json to improve user experience

Signed-off-by: Deluan <deluan@navidrome.org>

* format

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add margin to outlined input controls for improved spacing

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: remove redundant margin rule for last form control in array items

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: adjust font size of label elements in SchemaConfigEditor for improved readability

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

server/nativeapi/plugin.go

@@ -171,13 +171,26 @@ func isValidJSON(s string) bool {
 	return json.Unmarshal([]byte(s), &js) == nil
 }
 
-// validateAndUpdateConfig validates the config JSON and updates the plugin.
+// validateAndUpdateConfig validates the config JSON against the plugin's schema and updates the plugin.
 // Returns an error if validation or update fails (error response already written).
 func validateAndUpdateConfig(ctx context.Context, pm PluginManager, id, configJSON string, w http.ResponseWriter) error {
+	// Basic JSON syntax check
 	if configJSON != "" && !isValidJSON(configJSON) {
 		http.Error(w, "Invalid JSON in config field", http.StatusBadRequest)
 		return errors.New("invalid JSON")
 	}
+
+	// Validate against plugin's config schema
+	if err := pm.ValidatePluginConfig(ctx, id, configJSON); err != nil {
+		log.Warn(ctx, "Config validation failed", "id", id, err)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		// Try to return structured validation errors if available
+		response := map[string]any{"message": err.Error()}
+		_ = json.NewEncoder(w).Encode(response)
+		return err
+	}
+
 	if err := pm.UpdatePluginConfig(ctx, id, configJSON); err != nil {
 		log.Error(ctx, "Error updating plugin config", "id", id, err)
 		http.Error(w, "Error updating plugin configuration: "+err.Error(), http.StatusInternalServerError)