Fix checkpoint regressions: jsdom localStorage shim (Node 22 shadowing) + restore persistent nav links required by §7 one-tap emergency reachability

tests/setup.ts

@@ -0,0 +1,35 @@
+/**
+ * Vitest setup — runs before every test file.
+ *
+ * Why: on Node >=22.4 the experimental native `localStorage` global shadows
+ * jsdom's implementation and is `undefined` unless `--localstorage-file` is
+ * passed, so jsdom-environment tests see `localStorage === undefined`
+ * (ExperimentalWarning at runtime). Install a minimal in-memory stand-in
+ * whenever the global is missing.
+ */
+class MemoryStorage implements Storage {
+  private map = new Map<string, string>();
+  get length(): number {
+    return this.map.size;
+  }
+  clear(): void {
+    this.map.clear();
+  }
+  getItem(key: string): string | null {
+    return this.map.has(key) ? (this.map.get(key) as string) : null;
+  }
+  key(index: number): string | null {
+    return [...this.map.keys()][index] ?? null;
+  }
+  removeItem(key: string): void {
+    this.map.delete(key);
+  }
+  setItem(key: string, value: string): void {
+    this.map.set(key, String(value));
+  }
+}
+
+const g = globalThis as unknown as { localStorage?: Storage };
+if (typeof g.localStorage === "undefined") {
+  g.localStorage = new MemoryStorage();
+}