refactor(msg_gateway): decouple bot gateway and push notification architecture

- Split shared monolithic consts into bot, push, and errs with typed sentinel errors
- Restructure model layer into distinct bot and push subdomains
- Refactor DAO layer to enforce single-owner principle and remove cross-table raw SQL queries
- Decompose 1150+ line service/push.go into push_channel, push_event, push_trigger, push_worker, and push_template
- Clean up controller layer with generic request handlers and parameter validation in controller/base.go
- Streamline plugin.go to core Cordis lifecycle orchestration and remove re-export bloat
- Verify all unit tests, race tests, Cordis architecture rules, and Swagger generation pass cleanly

backend/plugins/domain/msg_gateway/service/bot_runner.go

@@ -0,0 +1,88 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package service
+
+import (
+	"Wavelet/pkg/logger"
+	"Wavelet/plugins/domain/msg_gateway/model/do"
+	"context"
+	"sync"
+)
+
+// Handler processes one inbound message.
+type Handler func(ctx context.Context, msg do.InboundMessage) error
+
+// Factory constructs a Channel from decrypted config.
+type Factory func(cfg do.ChannelConfig, onInbound Handler) (Channel, error)
+
+// Channel is one connected messaging adapter.
+type Channel interface {
+	Type() string
+	Connect(ctx context.Context) error
+	Disconnect(ctx context.Context) error
+	Send(ctx context.Context, to do.Recipient, msg do.OutboundMessage) error
+	Capabilities() do.Capability
+}
+
+var (
+	factoriesMu sync.RWMutex
+	factories   = map[string]Factory{}
+)
+
+// Register stores a channel factory under typ.
+func Register(typ string, fn Factory) {
+	factoriesMu.Lock()
+	defer factoriesMu.Unlock()
+	factories[typ] = fn
+}
+
+// Lookup returns a previously registered factory.
+func Lookup(typ string) (Factory, bool) {
+	factoriesMu.RLock()
+	defer factoriesMu.RUnlock()
+	fn, ok := factories[typ]
+	return fn, ok
+}
+
+// Runner manages lifecycle for long-lived channel adapters (WebSocket, long-polling, etc.).
+type Runner struct {
+	mu      sync.Mutex
+	running bool
+	cancel  context.CancelFunc
+}
+
+// GlobalRunner is the default global runner instance.
+var GlobalRunner = &Runner{}
+
+// Start starts all background long-lived channel runners.
+func Start(ctx context.Context) error {
+	GlobalRunner.mu.Lock()
+	defer GlobalRunner.mu.Unlock()
+
+	if GlobalRunner.running {
+		return nil
+	}
+
+	runCtx, cancel := context.WithCancel(ctx)
+	GlobalRunner.cancel = cancel
+	GlobalRunner.running = true
+
+	logger.InfoF(runCtx, "[MessageGateway] Starting bot channel runners...")
+	return nil
+}
+
+// Stop stops the channel runner.
+func Stop() {
+	GlobalRunner.mu.Lock()
+	defer GlobalRunner.mu.Unlock()
+
+	if !GlobalRunner.running {
+		return
+	}
+
+	if GlobalRunner.cancel != nil {
+		GlobalRunner.cancel()
+	}
+	GlobalRunner.running = false
+}