feat: add Office, PDF, and PPTX previews

tests/unit.spec.ts

@@ -9,6 +9,8 @@ import {
 import { loadPrefs, type SidebarSettingsClient } from '../src/client/prefs.ts'
 import { SIDEBAR_PREFS_DEFAULTS } from '../src/prefs-shared.ts'
 import { extOf, languageKeyForExt } from '../src/client/lang.ts'
+import { officeKindForExt } from '../src/client/office-types.ts'
+import { isPdfExt } from '../src/client/pdf-types.ts'
 import { relativeTo } from '../src/client/paths.ts'
 import { producedForClosing, resolveSidebarPath, selectProducedFiles } from '../src/client/produced-files.ts'
 import { defaultShell, ensureSpawnHelper } from '../src/pty-manager.ts'
@@ -453,6 +455,37 @@ describe('editor language mapping', () => {
   })
 })
 
+describe('office preview kind', () => {
+  it('routes docx/xlsx to their renderers', () => {
+    expect(officeKindForExt('.docx')).toBe('docx')
+    expect(officeKindForExt('.xlsx')).toBe('xlsx')
+  })
+
+  it('routes pptx to its renderer and legacy OLE formats to download-only', () => {
+    expect(officeKindForExt('.pptx')).toBe('pptx')
+    expect(officeKindForExt('.doc')).toBe('download-only')
+    expect(officeKindForExt('.xls')).toBe('download-only')
+    expect(officeKindForExt('.ppt')).toBe('download-only')
+  })
+
+  it('returns null for non-Office extensions and empty input', () => {
+    expect(officeKindForExt('.txt')).toBeNull()
+    expect(officeKindForExt('.md')).toBeNull()
+    expect(officeKindForExt('.png')).toBeNull()
+    expect(officeKindForExt('.pdf')).toBeNull()
+    expect(officeKindForExt('')).toBeNull()
+  })
+})
+
+describe('pdf preview kind', () => {
+  it('routes only .pdf to the browser-native preview', () => {
+    expect(isPdfExt('.pdf')).toBe(true)
+    expect(isPdfExt('.PDF')).toBe(false)
+    expect(isPdfExt('.docx')).toBe(false)
+    expect(isPdfExt('')).toBe(false)
+  })
+})
+
 describe('side card preferences', () => {
   /** A fake settings wire face whose settingsGet resolves to one raw value. */
   const wire = (value: unknown): SidebarSettingsClient => ({