fix(test): remove jsdom pragma + add window stub DOM surface

A/B fix per WorkBuddy review:
- browser-globals.ts: add addEventListener/removeEventListener/dispatchEvent
  to window stub, add compatMode to document stub
- Remove // @vitest-environment jsdom from 5 specs that only use
  renderToString/createElement (SSR, no DOM needed)

Test Files 131 passed (131), Tests 1367 passed, EXIT=0

tests/apes-tabs.spec.ts

@@ -1,4 +1,3 @@
-// @vitest-environment jsdom
 /**
  * apes:* tab registration tests (Phase 1/1b, C6: 3 tabs). The fork registers
  * its three information-layer tabs (agents / apps / profile) through the same

tests/browser-globals.ts

@@ -41,6 +41,9 @@ if (g.document === undefined) {
     querySelector: () => null,
     querySelectorAll: () => [],
     styleSheets: [],
+    // KaTeX probes compatMode at module load; without it it warns
+    // "doesn't work in quirks mode" and some layout paths no-op.
+    compatMode: 'CSS1Compat',
   }
 }
 
@@ -50,6 +53,9 @@ if (g.navigator === undefined) {
 
 if (g.window === undefined) {
   g.window = {
+    addEventListener: () => {},
+    removeEventListener: () => {},
+    dispatchEvent: () => true,
     clearTimeout: () => {},
     setTimeout: (_fn: () => void) => 0,
     innerWidth: 1024,

tests/builtins.spec.ts

@@ -1,4 +1,3 @@
-// @vitest-environment jsdom
 /**
  * Built-in registration tests: the plugin registers 7 tabs and 6 file
  * viewers through the same service external plugins use (dogfooding);

tests/markdown-copy-labels.spec.tsx

@@ -1,4 +1,3 @@
-// @vitest-environment jsdom
 /**
  * Markdown preview copy-label spec: the fence copy buttons ("复制" / "Copy")
  * must follow the DSH locale service through `codeLabels` — the DSH

tests/markdown-frontmatter.spec.tsx

@@ -1,4 +1,3 @@
-// @vitest-environment jsdom
 /**
  * Markdown frontmatter preview regression (#251): a leading, closed YAML
  * metadata block must not reach the shared MarkdownText parser, where its

tests/sandbox-views.spec.tsx

@@ -1,4 +1,3 @@
-// @vitest-environment jsdom
 /**
  * Sandbox-contract tests for the two built-in web surfaces (HTML preview
  * iframe and the browser tab iframe). The iframe sandbox — opaque origin,