refactor: migrate built-in plugins to SDK-only interface

- Six-phase plan complete: webui/cli/healthcheck/pluginmgr/clawhubadapter
  now interact with the kernel exclusively via internal/sdk interfaces;
  all Configure() calls and package-level global injection removed
- buildSDK in internal/plugin/registry.go is the single assembly point
- Add internal/sdk/events.go exporting event types/constants
- Fix ProviderManager cooldown sharing: LuaAdaptedProvider.Name() now
  returns the source name instead of lua_<adapter>, so multiple sources
  sharing an adapter (single script load via shared VM AdapterCache) no
  longer share failure-cooldown state
- Verified: build/vet/tests green, deployed to homeagent.service with
  full plugin capability testing via local OpenAI-compatible mock

internal/tracker/tracker.go

@@ -11,6 +11,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	sdk "gitcode.com/JianFeeeee/HomeAgent/internal/sdk"
 )
 
 type Tracker struct {
@@ -302,3 +304,6 @@ func (t *Tracker) Stats() map[string]interface{} {
 		"max_changeset_age": t.maxChangesetAge.String(),
 	}
 }
+
+// Tracker 直接满足内置 SDK 的 TrackerAPI（复用优先，无需独立适配器）。
+var _ sdk.TrackerAPI = (*Tracker)(nil)