fix: token persistence, context windows, CSS tables/bullets/hr, image attachments

- Fix token count reset on app restart: persist realTokens in conversation.json
- Fix token/context window values: Studio 150K (summarize at 120K), Terminal 100K
- Fix table rendering in terminal tab: correct thead/tbody display model
- Fix copy button always top-right in Studio code blocks
- Add markdown horizontal rule (---) support in Studio and Terminal
- Fix bullet list double dot: remove CSS ::before duplicate bullet point
- Add image attachments support (VLM description, file mentions @file.ext)
- Add sudo detection with cache (sync.Once)
- Fix message content serialization (TextContent wrapper)
- Guide AI to use read_file instead of cat in studio prompt

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

internal/api/conversation.go

@@ -13,22 +13,24 @@ import (
 	"github.com/muyue/muyue/internal/config"
 )
 
-const maxTokensApprox = 100000
-const summarizeThreshold = 80000
+const contextWindowTokens = 150000
+const summarizeRatio = 0.80
 const charsPerToken = 4
 
 type FeedMessage struct {
-	ID      string `json:"id"`
-	Role    string `json:"role"`
-	Content string `json:"content"`
-	Time    string `json:"time"`
+	ID      string   `json:"id"`
+	Role    string   `json:"role"`
+	Content string   `json:"content"`
+	Time    string   `json:"time"`
+	Images  []string `json:"images,omitempty"`
 }
 
 type Conversation struct {
-	Messages  []FeedMessage `json:"messages"`
-	Summary   string        `json:"summary,omitempty"`
-	CreatedAt string        `json:"created_at"`
-	UpdatedAt string        `json:"updated_at"`
+	Messages   []FeedMessage `json:"messages"`
+	Summary    string        `json:"summary,omitempty"`
+	RealTokens int           `json:"real_tokens,omitempty"`
+	CreatedAt  string        `json:"created_at"`
+	UpdatedAt  string        `json:"updated_at"`
 }
 
 type ConversationStore struct {
@@ -85,6 +87,7 @@ func (cs *ConversationStore) load() {
 		conv.Messages = []FeedMessage{}
 	}
 	cs.conv = &conv
+	cs.realTokens = conv.RealTokens
 }
 
 func (cs *ConversationStore) save() error {
@@ -127,15 +130,40 @@ func (cs *ConversationStore) Add(role, content string) FeedMessage {
 	return msg
 }
 
+func (cs *ConversationStore) AddWithImages(role, content string, imageIDs []string) FeedMessage {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
+	msg := FeedMessage{
+		ID:      generateMsgID(),
+		Role:    role,
+		Content: content,
+		Time:    time.Now().Format(time.RFC3339),
+		Images:  imageIDs,
+	}
+	cs.conv.Messages = append(cs.conv.Messages, msg)
+	cs.save()
+	return msg
+}
+
 func (cs *ConversationStore) Clear() {
 	cs.mu.Lock()
 	defer cs.mu.Unlock()
+
+	var imageIDs []string
+	for _, m := range cs.conv.Messages {
+		imageIDs = append(imageIDs, m.Images...)
+	}
+
 	cs.conv.Messages = []FeedMessage{}
 	cs.conv.Summary = ""
+	cs.conv.RealTokens = 0
 	cs.conv.CreatedAt = time.Now().Format(time.RFC3339)
 	cs.conv.UpdatedAt = time.Now().Format(time.RFC3339)
 	cs.realTokens = 0
 	cs.save()
+
+	go cleanupImages(imageIDs)
 }
 
 func (cs *ConversationStore) SetSummary(summary string) {
@@ -169,6 +197,7 @@ func (cs *ConversationStore) AddRealTokens(tokens int) {
 	}
 	cs.mu.Lock()
 	cs.realTokens += tokens
+	cs.conv.RealTokens = cs.realTokens
 	cs.mu.Unlock()
 }
 
@@ -196,7 +225,7 @@ func (cs *ConversationStore) ApproxTokenCountDetailed() TokenCount {
 }
 
 func (cs *ConversationStore) NeedsSummarization() bool {
-	return cs.ApproxTokenCount() > summarizeThreshold
+	return cs.ApproxTokenCount() > int(float64(contextWindowTokens)*summarizeRatio)
 }
 
 func (cs *ConversationStore) Search(query string) []SearchResult {