sdk: embed non-toolchain SDK in third_party, add NoMemory/Cleaner support

- Embed sdk/, example/, meta/, go.mod from homeagent-sdk (no .git)
- Core .gitignore excludes SDK toolchain: bin/, tools/, package/
- RegisterInputChannel + ChannelDef(NoMemory, Cleaner) in SDK
- IOManager input channel registry with GetInputChannelDef
- eventloop: apply channel Cleaner/NoMemory to interrupt text
- context engine: channelDefLookup applied in textForVector
- document store: ChannelCleaner param for archive functions
- All callers/adapters updated with ChannelDef{} default

internal/plugins/clawhubadapter/registry.go

@@ -190,7 +190,7 @@ func (r *ChannelRegistry) Dispatch(data json.RawMessage, pluginName string, sp *
 		caps = 1
 	}
 	desc := fmt.Sprintf("OC channel %s (from %s)", chName, pn)
-	s.RegisterOutputChannel(chName, caps, desc, func(args map[string]interface{}) (interface{}, error) {
+	s.RegisterOutputChannel(chName, caps, desc, sdk.ChannelDef{}, func(args map[string]interface{}) (interface{}, error) {
 		return sp.CallTool(chName, args)
 	})