修复: 技能面板视口按行收口与截断尾部乱码

- 技能列表视口改按行数切片（含描述行），修复变长条目撑爆面板
- 大文件截断改按 rune 边界回退，修复中文内容尾部乱码
- 补视口与截断边界测试

internal/skills.go

@@ -5,6 +5,7 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+	"unicode/utf8"
 
 	tea "charm.land/bubbletea/v2"
 )
@@ -215,16 +216,27 @@ func (m *Model) loadSkillContent(path string) {
 		m.Skills.ContentPath = path
 		return
 	}
-	content := string(data)
+	m.Skills.Content = truncateSkillContent(string(data), 100*1024)
-	// 限制内容大小，避免大文件卡顿
-	if len(content) > 100*1024 {
-		content = content[:100*1024] + "\n\n... (文件过大，截断显示)"
-	}
-	m.Skills.Content = content
 	m.Skills.ContentPath = path
 	m.Skills.ContentScroll = 0
 }
 
+// truncateSkillContent 限制内容大小避免大文件卡顿；截断点可能落在
+// UTF-8 多字节序列中间，逐字节回退到合法边界，避免尾部出现乱码
+func truncateSkillContent(content string, limit int) string {
+	if len(content) <= limit {
+		return content
+	}
+	content = content[:limit]
+	for len(content) > 0 {
+		if r, size := utf8.DecodeLastRuneInString(content); r != utf8.RuneError || size > 1 {
+			break
+		}
+		content = content[:len(content)-1]
+	}
+	return content + "\n\n... (文件过大，截断显示)"
+}
+
 // IsSkillsTab 判断当前是否在技能 tab
 func (m *Model) IsSkillsTab() bool {
 	return m.activeGroup == len(Groups)+1

internal/skills_test.go

@@ -0,0 +1,50 @@
+package internal
+
+import (
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+const truncSuffix = "\n\n... (文件过大，截断显示)"
+
+// TestTruncateSkillContentRuneBoundary 验证截断点落在多字节序列中间时
+// 逐字节回退到合法 rune 边界，结果不含残缺字节
+func TestTruncateSkillContentRuneBoundary(t *testing.T) {
+	limit := 100 * 1024
+	// 中文各 3 字节：分别构造截断点落在中文字符第 1、2 字节后的场景
+	for _, cutInChar := range []int{1, 2} {
+		prefix := strings.Repeat("a", limit-cutInChar)
+		content := prefix + "中文内容超出限制"
+		got := truncateSkillContent(content, limit)
+		body := strings.TrimSuffix(got, truncSuffix)
+		if !utf8.ValidString(body) {
+			t.Fatalf("截断点落在字符第 %d 字节后, 结果应为合法 UTF-8", cutInChar)
+		}
+		if !strings.HasPrefix(body, prefix) {
+			t.Fatalf("截断点落在字符第 %d 字节后, 不应吞掉 ASCII 前缀", cutInChar)
+		}
+		if len(body) > limit {
+			t.Fatalf("截断点落在字符第 %d 字节后, body 长度 %d 超限 %d", cutInChar, len(body), limit)
+		}
+		if !strings.HasSuffix(got, truncSuffix) {
+			t.Fatalf("截断后应带省略提示后缀, got %q", got[len(got)-40:])
+		}
+	}
+}
+
+// TestTruncateSkillContentEdge 验证边界：内容不超限原样返回，恰在边界截断不误删
+func TestTruncateSkillContentEdge(t *testing.T) {
+	limit := 100 * 1024
+	short := "短内容"
+	if got := truncateSkillContent(short, limit); got != short {
+		t.Fatalf("未超限内容应原样返回, got %q", got)
+	}
+	// 恰好 limit 字节后跟多字节字符：截断点在边界上，不应回退删掉合法内容
+	exact := strings.Repeat("a", limit)
+	got := truncateSkillContent(exact+"中文", limit)
+	body := strings.TrimSuffix(got, truncSuffix)
+	if body != exact {
+		t.Fatalf("边界截断不应删减合法内容, body 长度 = %d, 期望 %d", len(body), limit)
+	}
+}

internal/view_skills.go

@@ -65,10 +65,16 @@ func (m *Model) skillsListLines(w, listH int) []string {
 	if len(skills) == 0 {
 		return []string{style.DimFg.Render(fitWidth("  empty", w))}
 	}
-	start, end := viewport(m.Skills.SkillCur, len(skills), listH)
+	// 先为所有技能累积全部行（含描述行），再按行数视口切片，
-	var lines []string
+	// 避免按条目数计算视口导致变长行撑爆面板
-	for i := start; i < end; i++ {
+	type skillBlock struct {
-		sk := skills[i]
+		lines []string
+	}
+	var blocks []skillBlock
+	totalLines := 0
+	curLineOffset := 0
+
+	for i, sk := range skills {
 		cur := " "
 		if i == m.Skills.SkillCur {
 			cur = "▸"
@@ -78,7 +84,7 @@ func (m *Model) skillsListLines(w, listH int) []string {
 		if i == m.Skills.SkillCur && m.Skills.FocusPanel == 0 {
 			sty = style.SelStyle
 		}
-		lines = append(lines, sty.Render(padRightByWidth(truncateByWidth(line, w), w)))
+		blockLines := []string{sty.Render(padRightByWidth(truncateByWidth(line, w), w))}
 		// 如果有描述，追加一行
 		if sk.Description != "" {
 			descLine := "   " + sk.Description
@@ -86,10 +92,25 @@ func (m *Model) skillsListLines(w, listH int) []string {
 			if i == m.Skills.SkillCur && m.Skills.FocusPanel == 0 {
 				descSty = style.SelStyle
 			}
-			lines = append(lines, descSty.Render(padRightByWidth(truncateByWidth(descLine, w), w)))
+			blockLines = append(blockLines, descSty.Render(padRightByWidth(truncateByWidth(descLine, w), w)))
 		}
+		if i == m.Skills.SkillCur {
+			curLineOffset = totalLines
 		}
-	return lines
+		totalLines += len(blockLines)
+		blocks = append(blocks, skillBlock{lines: blockLines})
+	}
+
+	start, end := viewport(curLineOffset, totalLines, listH)
+
+	var allLines []string
+	for _, b := range blocks {
+		allLines = append(allLines, b.lines...)
+	}
+	if end > len(allLines) {
+		end = len(allLines)
+	}
+	return allLines[start:end]
 }
 
 func (m *Model) skillsFileLines(w, listH int) []string {

internal/view_skills_test.go

@@ -0,0 +1,32 @@
+package internal
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestSkillsListLinesViewportByLines 验证技能列表视口按行数（含描述行）收口，
+// 返回行数不超过 listH，避免变长行撑爆面板
+func TestSkillsListLinesViewportByLines(t *testing.T) {
+	m := NewModel()
+	m.Skills.Loaded = true
+	for i := 0; i < 3; i++ {
+		m.Skills.Skills = append(m.Skills.Skills, &SkillInfo{
+			Name:        "skill-" + strings.Repeat("x", i),
+			Description: "描述行 " + string(rune('A'+i)),
+		})
+	}
+	m.Skills.SkillCur = 0
+	m.Skills.FocusPanel = 0
+
+	listH := 3 // 足够只显示部分（总共 6 行：3 技能 × 2 行）
+	lines := m.skillsListLines(30, listH)
+	if len(lines) > listH {
+		t.Fatalf("skillsListLines 应返回 ≤ %d 行, got %d", listH, len(lines))
+	}
+
+	// 光标在首个技能时，视口应从头开始且光标行可见
+	if !strings.Contains(lines[0], "▸") {
+		t.Fatalf("首行应含光标标记, got %q", lines[0])
+	}
+}