feat: sdk NoMemory/Cleaner + example build fixes

- sdk/plugin.go: ToolDef adds NoMemory/Cleaner fields
- sdk/plugin_test.go: unit tests for NoMemory/Cleaner
- all example plugins: NoMemory/Cleaner annotated for each tool
- plugindev/templates.go: template shows NoMemory/Cleaner pattern
- plugindev/cmd_build.go: fix ensureGoMod, buildBundle/buildTarget sdkPath param, NewPluginFactory
- example/go.mod: add external dependency declarations (chromedp, gofeed)
- add main.go stubs for all example plugins

example/music/go.mod

@@ -2,6 +2,6 @@ module music
 
 go 1.25.0
 
-require gitcode.com/JianFeeeee/homeagent-sdk v0.7.1
+require gitcode.com/JianFeeeee/homeagent-sdk v0.0.0
 
-replace gitcode.com/JianFeeeee/homeagent-sdk => /tmp/opencode/sdk-clone
+replace gitcode.com/JianFeeeee/homeagent-sdk => E:/program/homeagent/homeagentsdk

example/music/main.go

@@ -0,0 +1,11 @@
+//go:build !windows || !cgo
+
+package main
+
+import (
+	sdk "gitcode.com/JianFeeeee/homeagent-sdk/sdk"
+)
+
+func NewPlugin(name string, config map[string]interface{}) (sdk.Plugin, error) {
+	return NewPluginFactory(name, config)
+}

example/music/plugin.go

@@ -56,7 +56,7 @@ type lyricData struct {
 	Lyric string `json:"lyric"`
 }
 
-func NewPlugin(name string, config map[string]interface{}) (sdk.Plugin, error) {
+func NewPluginFactory(name string, config map[string]interface{}) (sdk.Plugin, error) {
 	return &Plugin{name: name}, nil
 }
 
@@ -84,6 +84,13 @@ func (p *Plugin) Start(s *sdk.PluginSDK) error {
 			},
 			"required": []string{"keyword"},
 		},
+		Cleaner: func(output string) string {
+			var r struct{ Content string }
+			if json.Unmarshal([]byte(output), &r) == nil && r.Content != "" {
+				return r.Content
+			}
+			return output
+		},
 	}, p.handleSearch)
 
 	s.RegisterTool(p.name+"_lyrics", sdk.ToolDef{