refactor: redesign Config as settings window with sidebar panels, remove system overview from Dashboard

- Config: sidebar navigation with 5 panels (Profile, AI Providers, Updates, Locale, Skills)
- Dashboard: remove duplicated system overview section, keep workflows and activity log
- New CSS for config window layout, cards, provider cards, update rows
- Add i18n panel keys (FR/EN)

💾 Generated with Crush

Assisted-by: GLM-5-Turbo via Crush <crush@charm.land>

internal/api/conversation.go

@@ -0,0 +1,157 @@
+package api
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+	"unicode/utf8"
+
+	"github.com/muyue/muyue/internal/config"
+)
+
+const maxTokensApprox = 100000
+const summarizeThreshold = 80000
+const charsPerToken = 4
+
+type FeedMessage struct {
+	ID      string `json:"id"`
+	Role    string `json:"role"`
+	Content string `json:"content"`
+	Time    string `json:"time"`
+}
+
+type Conversation struct {
+	Messages  []FeedMessage `json:"messages"`
+	Summary   string        `json:"summary,omitempty"`
+	CreatedAt string        `json:"created_at"`
+	UpdatedAt string        `json:"updated_at"`
+}
+
+type ConversationStore struct {
+	mu   sync.RWMutex
+	path string
+	conv *Conversation
+}
+
+func NewConversationStore() *ConversationStore {
+	dir, err := config.ConfigDir()
+	if err != nil {
+		dir = "/tmp/muyue"
+	}
+	path := filepath.Join(dir, "conversation.json")
+	cs := &ConversationStore{path: path}
+	cs.load()
+	return cs
+}
+
+func (cs *ConversationStore) load() {
+	data, err := os.ReadFile(cs.path)
+	if err != nil {
+		cs.conv = &Conversation{
+			Messages:  []FeedMessage{},
+			CreatedAt: time.Now().Format(time.RFC3339),
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		}
+		return
+	}
+	var conv Conversation
+	if err := json.Unmarshal(data, &conv); err != nil {
+		cs.conv = &Conversation{
+			Messages:  []FeedMessage{},
+			CreatedAt: time.Now().Format(time.RFC3339),
+			UpdatedAt: time.Now().Format(time.RFC3339),
+		}
+		return
+	}
+	if conv.Messages == nil {
+		conv.Messages = []FeedMessage{}
+	}
+	cs.conv = &conv
+}
+
+func (cs *ConversationStore) save() error {
+	cs.conv.UpdatedAt = time.Now().Format(time.RFC3339)
+	data, err := json.MarshalIndent(cs.conv, "", "  ")
+	if err != nil {
+		return err
+	}
+	dir := filepath.Dir(cs.path)
+	os.MkdirAll(dir, 0755)
+	return os.WriteFile(cs.path, data, 0600)
+}
+
+func (cs *ConversationStore) Get() []FeedMessage {
+	cs.mu.RLock()
+	defer cs.mu.RUnlock()
+	out := make([]FeedMessage, len(cs.conv.Messages))
+	copy(out, cs.conv.Messages)
+	return out
+}
+
+func (cs *ConversationStore) GetSummary() string {
+	cs.mu.RLock()
+	defer cs.mu.RUnlock()
+	return cs.conv.Summary
+}
+
+func (cs *ConversationStore) Add(role, content string) FeedMessage {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
+	msg := FeedMessage{
+		ID:      generateMsgID(),
+		Role:    role,
+		Content: content,
+		Time:    time.Now().Format(time.RFC3339),
+	}
+	cs.conv.Messages = append(cs.conv.Messages, msg)
+	cs.save()
+	return msg
+}
+
+func (cs *ConversationStore) Clear() {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+	cs.conv.Messages = []FeedMessage{}
+	cs.conv.Summary = ""
+	cs.conv.CreatedAt = time.Now().Format(time.RFC3339)
+	cs.conv.UpdatedAt = time.Now().Format(time.RFC3339)
+	cs.save()
+}
+
+func (cs *ConversationStore) SetSummary(summary string) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+	cs.conv.Summary = summary
+	cs.save()
+}
+
+func (cs *ConversationStore) TrimOld(keepCount int) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+	if len(cs.conv.Messages) <= keepCount {
+		return
+	}
+	cs.conv.Messages = cs.conv.Messages[len(cs.conv.Messages)-keepCount:]
+	cs.save()
+}
+
+func (cs *ConversationStore) ApproxTokenCount() int {
+	cs.mu.RLock()
+	defer cs.mu.RUnlock()
+	total := utf8.RuneCountInString(cs.conv.Summary)
+	for _, m := range cs.conv.Messages {
+		total += utf8.RuneCountInString(m.Content)
+	}
+	return total / charsPerToken
+}
+
+func (cs *ConversationStore) NeedsSummarization() bool {
+	return cs.ApproxTokenCount() > summarizeThreshold
+}
+
+func generateMsgID() string {
+	return time.Now().Format("20060102150405.000")
+}