feat: 终端二级设置支持自定义字体（字体族 + 9–32px 字号，实时生效）

- SidebarPrefs 新增 terminalFontFamily（空 = 跟随主题等宽字体）/ terminalFontSize（9–32，默认 13），PrefsSchema 与 parsePrefs 同步校验
- 声明式设置 API 扩展：SidebarSettingToggle 支持 type: 'switch' | 'text' | 'number'（缺省 switch，向后兼容）+ min/max/placeholder/unit
- 终端卡片齿轮弹窗新增「终端字体」「终端字号」两行：blur/Enter 提交、number 钳制、提交失败回滚草稿
- TerminalView 经 store 订阅实时应用字体（options + re-fit + resize），懒加载 chunk 无新增依赖
- 新增 resolveTerminalFont 纯函数（回退链：用户字体 → 主题 token → 内置等宽栈）并单测
- 版本 0.11.0，README/AGENTS.md/设计文档同步

tests/plugin-shape.spec.ts

@@ -50,6 +50,10 @@ describe('dsh-better-sidebar plugin export shape', () => {
     // The terminal tools default OFF (the feature is dormant until the user
     // enables it in the side card settings).
     expect(resolved.agentTerminalTools).toBe(false)
+    // The terminal font customizations default to the theme (empty family)
+    // and 13px.
+    expect(resolved.terminalFontFamily).toBe('')
+    expect(resolved.terminalFontSize).toBe(13)
     // The enable-switch maps resolve to {} (everything on) for old documents.
     expect(resolved.tabsEnabled).toEqual({})
     expect(resolved.viewersEnabled).toEqual({})
@@ -59,6 +63,6 @@ describe('dsh-better-sidebar plugin export shape', () => {
     const overridden = (PrefsSchema as unknown as {
       (input: Record<string, unknown> | undefined): Record<string, unknown>
     })({ openByDefault: false, defaultWidthPercent: 45 })
-    expect(overridden).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, bottomPanelAutoTerminal: true, interceptOpenPath: true, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, tabsEnabled: {}, viewersEnabled: {} })
+    expect(overridden).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, tabsEnabled: {}, viewersEnabled: {} })
   })
 })