refactor: pluginize text cleaning and tool NoMemory control

- SDK: ToolDef.NoMemory field, PluginSDK.RegisterTextCleaner/TextCleaners
- Registry: aggregate text cleaners from plugins, expose CleanText()
- Memory: replace hardcoded QQ regex CleanTemplateText with dynamic CleanText/SetTextCleaner
- StageHost: add ToolDef(name) lookup
- eventloop: check ToolDef.NoMemory before emitMemoryCandidate
- context/Prune: replace hardcoded agentcli/terminal source filter with ToolsUsed NoMemory check
- agentcli/cmd: mark tools with NoMemory: true
- main.go: wire memory.SetTextCleaner(pluginReg.CleanText)

internal/memory/cut.go

@@ -93,7 +93,7 @@ var stopWords = map[string]bool{
 }
 
 func ExtractKeywords(text string) []string {
-	text = CleanTemplateText(text)
+	text = CleanText(text)
 	x := GetJieba()
 	if x == nil {
 		return nil
@@ -120,7 +120,7 @@ func ExtractKeywords(text string) []string {
 
 // CutExact 精确模式分词：返回去停用词后的所有有义项（不限数量），用于 doc→graph 蒸馏
 func CutExact(text string) []string {
-	text = CleanTemplateText(text)
+	text = CleanText(text)
 	x := GetJieba()
 	if x == nil {
 		return nil