feat: 提交详情能看 diff，也能丢给 AI 审这一次改动。文件检查可单独排除路径，TODO 只认大写，避免把 todo 表和模块当成待办标记。

热力图按容器宽度铺满一年，不再横向滚动。托盘右键换成可换皮肤的弹层；更新下载显示进度，退出后再由脚本拉起安装器，避免还占着 exe。

ai.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"view/service"
 	"view/service/ai"
 )
 
@@ -145,6 +146,49 @@ type aiStreamEvent struct {
 // SendAIMessage 发送一条用户消息并启动流式回复。
 // conversationID 为 0 时自动创建会话；scenario: chat | project | git | todo | ticket。
 func (a *App) SendAIMessage(conversationID, projectID int64, scenario, content string) (AIConversation, error) {
+	return a.startAIChat(conversationID, projectID, scenario, content, "", "")
+}
+
+// SendAIDiffMessage 针对某次提交的 diff 发起 AI 分析；后续同会话追问仍带上该 diff。
+func (a *App) SendAIDiffMessage(conversationID, projectID int64, hash, content string) (AIConversation, error) {
+	hash = strings.TrimSpace(hash)
+	if hash == "" {
+		return AIConversation{}, errors.New("GIT_REF_NOT_FOUND")
+	}
+	if e := a.ready(); e != nil {
+		return AIConversation{}, e
+	}
+	if projectID <= 0 && conversationID > 0 {
+		convs, _ := a.store.ListAIConversations(0)
+		for _, c := range convs {
+			if c.ID == conversationID {
+				projectID = c.ProjectID
+				break
+			}
+		}
+	}
+	p, e := a.store.GetProject(projectID)
+	if e != nil {
+		return AIConversation{}, e
+	}
+	d, e := (GitAnalyzer{}).CommitDetail(a.ctx, p.Path, hash)
+	if e != nil {
+		return AIConversation{}, e
+	}
+	title := strings.TrimSpace(d.Message)
+	if title == "" {
+		title = content
+	}
+	if r := []rune(title); len(r) > 36 {
+		title = string(r[:36]) + "…"
+	}
+	if !strings.HasPrefix(strings.ToLower(title), "diff") {
+		title = "Diff: " + title
+	}
+	return a.startAIChat(conversationID, projectID, "diff", content, service.FormatCommitDiffForAI(d, 0), title)
+}
+
+func (a *App) startAIChat(conversationID, projectID int64, scenario, content, extraSystem, title string) (AIConversation, error) {
 	if e := a.ready(); e != nil {
 		return AIConversation{}, e
 	}
@@ -166,7 +210,9 @@ func (a *App) SendAIMessage(conversationID, projectID int64, scenario, content s
 
 	var conv AIConversation
 	if conversationID == 0 {
-		title := content
+		if strings.TrimSpace(title) == "" {
+			title = content
+		}
 		if r := []rune(title); len(r) > 40 {
 			title = string(r[:40]) + "…"
 		}
@@ -197,9 +243,19 @@ func (a *App) SendAIMessage(conversationID, projectID int64, scenario, content s
 	a.aiStreams[conv.ID] = cancel
 	a.mu.Unlock()
 
-	// 组装消息：场景系统提示词 + 最近历史 + 本条用户消息。
+	sys := a.buildAIContext(projectID, scenario, st.Locale)
+	if extraSystem != "" {
+		sys = strings.TrimRight(sys, "\n") + "\n\n" + extraSystem
+		if scenario == "diff" {
+			if st.Locale == "en" {
+				sys += "\nTask: Review this commit's diff. Cover intent, risks, missing tests, and brief improvements. Use only the diff above; do not invent changes.\n"
+			} else {
+				sys += "\n任务：审查这次提交的 diff，说明改动意图、潜在风险、遗漏测试，并给出简要改进建议。只依据上面的 diff，不要编造未出现的改动。\n"
+			}
+		}
+	}
 	history, _ := a.store.ListAIMessages(conv.ID)
-	msgs := []ai.Message{{Role: "system", Content: a.buildAIContext(projectID, scenario, st.Locale)}}
+	msgs := []ai.Message{{Role: "system", Content: sys}}
 	if len(history) > 20 {
 		history = history[len(history)-20:]
 	}