refactor(core): decouple gin from pkg/util and reduce code duplication

backend/core/extpoints/migration.go

@@ -19,27 +19,26 @@ type MigrationEntry struct {
 // MigrationExtension defines the interface for registering and querying plugin migrations.
 type MigrationExtension interface {
 	Register(pluginID string, fsys fs.FS, dir ...string)
+	Unregister(pluginID string) bool
 	Entries() []MigrationEntry
 	Get(pluginID string) (MigrationEntry, bool)
-	Unregister(pluginID string) bool
 }
 
-// MigrationRegistry collects and stores migration entries from plugins.
+// MigrationRegistry implements MigrationExtension.
 type MigrationRegistry struct {
 	mu      sync.RWMutex
 	entries []MigrationEntry
 	lookup  map[string]MigrationEntry
 }
 
-// NewMigrationRegistry creates a new migration registry.
+// NewMigrationRegistry creates a new MigrationRegistry.
 func NewMigrationRegistry() *MigrationRegistry {
 	return &MigrationRegistry{
 		lookup: make(map[string]MigrationEntry),
 	}
 }
 
-// Register adds a migration entry for a plugin.
-// If dir is not specified, it defaults to "migrations".
+// Register registers an embedded migration filesystem for a plugin.
 func (m *MigrationRegistry) Register(pluginID string, fsys fs.FS, dir ...string) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -72,21 +71,9 @@ func (m *MigrationRegistry) Register(pluginID string, fsys fs.FS, dir ...string)
 
 // Unregister removes a registered migration entry by plugin ID.
 func (m *MigrationRegistry) Unregister(pluginID string) bool {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if _, exists := m.lookup[pluginID]; !exists {
-		return false
-	}
-
-	delete(m.lookup, pluginID)
-	for i, e := range m.entries {
-		if e.PluginID == pluginID {
-			m.entries = append(m.entries[:i], m.entries[i+1:]...)
-			break
-		}
-	}
-	return true
+	return unregisterEntry(&m.mu, m.lookup, &m.entries, pluginID, func(e MigrationEntry) bool {
+		return e.PluginID == pluginID
+	})
 }
 
 // Entries returns a copy of all registered migration entries in registration order.

backend/core/extpoints/registry.go

@@ -0,0 +1,22 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package extpoints
+
+import (
+	"slices"
+	"sync"
+)
+
+func unregisterEntry[T any](mu *sync.RWMutex, lookup map[string]T, list *[]T, key string, matches func(T) bool) bool {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if _, exists := lookup[key]; !exists {
+		return false
+	}
+
+	delete(lookup, key)
+	*list = slices.DeleteFunc(*list, matches)
+	return true
+}

backend/core/extpoints/schedule.go

@@ -88,21 +88,9 @@ func (s *ScheduleRegistry) RegisterCron(spec, taskType string, payload any, opts
 
 // Unregister removes a registered schedule definition by its task type.
 func (s *ScheduleRegistry) Unregister(taskType string) bool {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	if _, exists := s.lookup[taskType]; !exists {
-		return false
-	}
-
-	delete(s.lookup, taskType)
-	for i, item := range s.schedules {
-		if item.TaskType == taskType {
-			s.schedules = append(s.schedules[:i], s.schedules[i+1:]...)
-			break
-		}
-	}
-	return true
+	return unregisterEntry(&s.mu, s.lookup, &s.schedules, taskType, func(item ScheduleDefinition) bool {
+		return item.TaskType == taskType
+	})
 }
 
 // Schedules returns a copy of all registered ScheduleDefinitions.

backend/core/extpoints/setting.go

@@ -65,21 +65,9 @@ func (s *SettingRegistry) Register(schema SettingSchema) {
 
 // Unregister removes a registered SettingSchema by its key.
 func (s *SettingRegistry) Unregister(key string) bool {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	if _, exists := s.lookup[key]; !exists {
-		return false
-	}
-
-	delete(s.lookup, key)
-	for i, item := range s.schemas {
-		if item.Key == key {
-			s.schemas = append(s.schemas[:i], s.schemas[i+1:]...)
-			break
-		}
-	}
-	return true
+	return unregisterEntry(&s.mu, s.lookup, &s.schemas, key, func(item SettingSchema) bool {
+		return item.Key == key
+	})
 }
 
 // Schemas returns a copy of all registered SettingSchemas.

backend/core/extpoints/task.go

@@ -107,21 +107,9 @@ func (t *TaskRegistry) Register(pattern string, handler any, opts ...TaskOption)
 
 // Unregister removes a registered task definition by its pattern.
 func (t *TaskRegistry) Unregister(pattern string) bool {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	if _, exists := t.lookup[pattern]; !exists {
-		return false
-	}
-
-	delete(t.lookup, pattern)
-	for i, item := range t.tasks {
-		if item.Pattern == pattern {
-			t.tasks = append(t.tasks[:i], t.tasks[i+1:]...)
-			break
-		}
-	}
-	return true
+	return unregisterEntry(&t.mu, t.lookup, &t.tasks, pattern, func(item TaskDefinition) bool {
+		return item.Pattern == pattern
+	})
 }
 
 // Tasks returns a copy of all registered TaskDefinitions.