fix(plugins): clear plugin errors on startup to allow retrying

Plugins that entered an error state (e.g., incompatible with the
Navidrome version) would remain in that state across restarts, blocking
the user from retrying. This adds a ClearErrors method to
PluginRepository that resets the last_error field on all plugins, and
calls it during plugin manager startup before syncing and loading.

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

model/plugin.go

@@ -23,6 +23,7 @@ type Plugins []Plugin
 
 type PluginRepository interface {
 	ResourceRepository
+	ClearErrors() error
 	CountAll(options ...QueryOptions) (int64, error)
 	Delete(id string) error
 	Get(id string) (*Plugin, error)

persistence/plugin_repository.go

@@ -31,6 +31,14 @@ func (r *pluginRepository) isPermitted() bool {
 	return user.IsAdmin
 }
 
+func (r *pluginRepository) ClearErrors() error {
+	if !r.isPermitted() {
+		return rest.ErrPermissionDenied
+	}
+	_, err := r.db.NewQuery("UPDATE plugin SET last_error = '' WHERE last_error != ''").Execute()
+	return err
+}
+
 func (r *pluginRepository) CountAll(options ...model.QueryOptions) (int64, error) {
 	if !r.isPermitted() {
 		return 0, rest.ErrPermissionDenied

persistence/plugin_repository_test.go

@@ -175,6 +175,30 @@ var _ = Describe("PluginRepository", func() {
 				Expect(err.Error()).To(ContainSubstring("ID cannot be empty"))
 			})
 		})
+
+		Describe("ClearErrors", func() {
+			It("clears last_error on all plugins with errors", func() {
+				_ = repo.Put(&model.Plugin{ID: "ok-plugin", Path: "/plugins/ok.wasm", Manifest: "{}", SHA256: "h1"})
+				_ = repo.Put(&model.Plugin{ID: "err-plugin-1", Path: "/plugins/e1.wasm", Manifest: "{}", SHA256: "h2", LastError: "incompatible version"})
+				_ = repo.Put(&model.Plugin{ID: "err-plugin-2", Path: "/plugins/e2.wasm", Manifest: "{}", SHA256: "h3", LastError: "missing export"})
+
+				err := repo.ClearErrors()
+				Expect(err).To(BeNil())
+
+				all, err := repo.GetAll()
+				Expect(err).To(BeNil())
+				for _, p := range all {
+					Expect(p.LastError).To(BeEmpty(), "plugin %s should have no error", p.ID)
+				}
+			})
+
+			It("succeeds when no plugins have errors", func() {
+				_ = repo.Put(&model.Plugin{ID: "clean-plugin", Path: "/plugins/c.wasm", Manifest: "{}", SHA256: "h1"})
+
+				err := repo.ClearErrors()
+				Expect(err).To(BeNil())
+			})
+		})
 	})
 
 	Describe("Regular User", func() {

plugins/manager.go

@@ -146,6 +146,12 @@ func (m *Manager) Start(ctx context.Context) error {
 
 	log.Info(ctx, "Starting plugin manager", "folder", folder)
 
+	// Clear previous error states so plugins can be retried on restart
+	adminCtx := adminContext(ctx)
+	if err := m.ds.Plugin(adminCtx).ClearErrors(); err != nil {
+		log.Error(ctx, "Error clearing plugin errors", err)
+	}
+
 	// Sync plugins folder with DB
 	if err := m.syncPlugins(ctx, folder); err != nil {
 		log.Error(ctx, "Error syncing plugins with DB", err)

tests/mock_plugin_repo.go

@@ -29,6 +29,20 @@ func (m *MockPluginRepo) SetError(err bool) {
 	m.Err = err
 }
 
+func (m *MockPluginRepo) ClearErrors() error {
+	if m.Err {
+		return errors.New("unexpected error")
+	}
+	for i := range m.All {
+		m.All[i].LastError = ""
+	}
+	for k, p := range m.Data {
+		p.LastError = ""
+		m.Data[k] = p
+	}
+	return nil
+}
+
 func (m *MockPluginRepo) SetData(plugins model.Plugins) {
 	m.Data = make(map[string]*model.Plugin, len(plugins))
 	m.All = plugins