fix: 0.9.1 快照收尾修复与稳健性增强 - 快照目录对归一化匹配（Windows同目录异写不误拦、与scanCacheStore同款逻辑双向同步）、截断结果保存快照拦截提示（防对照新文件误报）、folder:scan IPC校验抽scanIpc纯逻辑模块单测全覆盖（缓存源选择惰性读盘）、对照模式导出报告附变迁对照表（三格式当前/基线状态与大小、标签收敛SNAPSHOT_CHANGE_LABEL共享映射、E2E对照导出写盘断言）、顶层ErrorBoundary渲染兜底（错误面板一键重载防白屏）、文档四件套同步

src/main/scanIpc.test.ts

@@ -0,0 +1,99 @@
+import { describe, it, expect } from 'vitest'
+import type { ScanCacheEntry } from './folderScan'
+import { isScanCacheEntries, resolveScanArgs } from './scanIpc'
+
+/** 构造一条合法缓存条目（IPC 形态校验只看 rel/status 字符串字段） */
+function entry(rel: string): ScanCacheEntry {
+  return { rel, leftFp: { size: 1, mtime: 100 }, rightFp: { size: 1, mtime: 100 }, status: 'same', semSame: null }
+}
+
+/** 盘上缓存读取 stub：返回指定缓存并记录调用 */
+function storedLoader(cache: ScanCacheEntry[] | null): (() => ScanCacheEntry[] | null) & { calls: number } {
+  const f = (): ScanCacheEntry[] | null => {
+    f.calls++
+    return cache
+  }
+  f.calls = 0
+  return f
+}
+
+describe('isScanCacheEntries - IPC 形态校验', () => {
+  it('合法缓存数组通过（rel/status 为字符串）', () => {
+    expect(isScanCacheEntries([])).toBe(true)
+    expect(isScanCacheEntries([entry('a.txt'), entry('b.txt')])).toBe(true)
+  })
+
+  it('非数组 / 含非对象 / rel 或 status 非字符串拒绝', () => {
+    expect(isScanCacheEntries(null)).toBe(false)
+    expect(isScanCacheEntries(undefined)).toBe(false)
+    expect(isScanCacheEntries('cache')).toBe(false)
+    expect(isScanCacheEntries([entry('a.txt'), null])).toBe(false)
+    expect(isScanCacheEntries([entry('a.txt'), 'garbage'])).toBe(false)
+    expect(isScanCacheEntries([{ rel: 42, status: 'same' }])).toBe(false)
+    expect(isScanCacheEntries([{ rel: 'a.txt', status: 1 }])).toBe(false)
+    expect(isScanCacheEntries([{ rel: 'a.txt' }])).toBe(false)
+  })
+})
+
+describe('resolveScanArgs - 缓存源选择与忽略规则校验', () => {
+  it('渲染端携带合法内存缓存：原样传递且不读盘（惰性）', () => {
+    const stored = storedLoader([entry('disk.txt')])
+    const mem = [entry('mem.txt')]
+    const r = resolveScanArgs(mem, undefined, stored)
+    expect(r.previous).toBe(mem)
+    expect(stored.calls).toBe(0)
+  })
+
+  it('内存缓存为空数组（合法形态）：使用空数组，同样不注入盘上缓存', () => {
+    // 空数组是同目录上次扫描的最新形态（如空目录对），应优先于可能过期的盘上缓存
+    const stored = storedLoader([entry('disk.txt')])
+    const r = resolveScanArgs([], undefined, stored)
+    expect(r.previous).toEqual([])
+    expect(stored.calls).toBe(0)
+  })
+
+  it('未携带 / 形态非法的内存缓存：回退盘上缓存（惰性读盘一次）', () => {
+    const disk = [entry('disk.txt')]
+    for (const bad of [undefined, null, 'x', [{ rel: 1, status: 'same' }]] as unknown[]) {
+      const stored = storedLoader(disk)
+      const r = resolveScanArgs(bad, undefined, stored)
+      expect(r.previous).toBe(disk)
+      expect(stored.calls).toBe(1)
+    }
+  })
+
+  it('盘上缓存为 null 或空数组：不注入 previous（全量扫描）', () => {
+    expect(resolveScanArgs(undefined, undefined, storedLoader(null)).previous).toBeUndefined()
+    expect(resolveScanArgs(undefined, undefined, storedLoader([])).previous).toBeUndefined()
+  })
+
+  it('忽略规则合法字符串数组传递（空数组合法）', () => {
+    expect(resolveScanArgs(undefined, ['node_modules/', '*.log'], storedLoader(null)).ignore).toEqual([
+      'node_modules/',
+      '*.log'
+    ])
+    expect(resolveScanArgs(undefined, [], storedLoader(null)).ignore).toEqual([])
+  })
+
+  it('忽略规则非法形态（非数组/含非字符串/超条数）整体忽略', () => {
+    expect(resolveScanArgs(undefined, null, storedLoader(null)).ignore).toBeUndefined()
+    expect(resolveScanArgs(undefined, 'node_modules/', storedLoader(null)).ignore).toBeUndefined()
+    expect(resolveScanArgs(undefined, ['a', 42], storedLoader(null)).ignore).toBeUndefined()
+    expect(
+      resolveScanArgs(
+        undefined,
+        Array.from({ length: 51 }, () => 'a'),
+        storedLoader(null)
+      ).ignore
+    ).toBeUndefined()
+  })
+
+  it('组合：内存缓存非法 + 忽略规则合法 + 盘上缓存有效', () => {
+    const disk = [entry('disk.txt')]
+    const stored = storedLoader(disk)
+    const r = resolveScanArgs([{ rel: 'bad' }], ['dist/'], stored)
+    expect(r.previous).toBe(disk)
+    expect(r.ignore).toEqual(['dist/'])
+    expect(stored.calls).toBe(1)
+  })
+})