refactor(i18n): delete 523 duplicated strings; move the legal controls to the source

apps/web/src/locales/__tests__/legalShadow.test.ts

@@ -0,0 +1,51 @@
+import { describe, it, expect } from 'vitest'
+import { readFileSync } from 'node:fs'
+import { resolve } from 'node:path'
+
+/**
+ * Web may not shadow the namespaces whose wording is a legal or compliance
+ * commitment.
+ *
+ * This replaces four deep-equality assertions that checked two copies of the
+ * privacy policy, the terms and the assistant-handoff copy said the same thing.
+ * They had drifted before — mobile's Terms went months without the uploads
+ * warranty, the DMCA route or the liability cap, and the handoff `lead` was
+ * rewritten shorter on one platform and had to be put back.
+ *
+ * There is one copy now, in `packages/shared/src/i18n/en.json`, and this file
+ * guards the only way the old problem could come back: web's overlay silently
+ * reintroducing a second version of one of these strings. "Two files must match"
+ * became "there is one file and web may not override it" — strictly stronger,
+ * because it also catches a divergence nobody thought to add an assertion for.
+ *
+ * The content rules themselves moved to `packages/shared/src/i18n/legalContent.test.ts`,
+ * next to the file they describe.
+ */
+const overrides = JSON.parse(readFileSync(resolve(__dirname, '../en.json'), 'utf8'))
+
+/** Top-level namespace → why web is not allowed to have its own version. */
+const PROTECTED: Record<string, string> = {
+  privacy: 'Google Play reads this policy from the store-listing URL; the app renders the same words.',
+  terms: 'A contract. Two versions of it is two contracts.',
+}
+
+/** `namespace.child` paths that are equally off-limits. */
+const PROTECTED_PATHS: Record<string, string> = {
+  'library.insights': 'Tells the reader what came back from the assistant; drifted once already.',
+  'library.discuss': 'Tells the reader what the handoff button does; drifted once already.',
+}
+
+describe('web overlay does not shadow shared legal copy', () => {
+  for (const [ns, why] of Object.entries(PROTECTED)) {
+    it(`has no ${ns}.* of its own — ${why}`, () => {
+      expect(overrides[ns]).toBeUndefined()
+    })
+  }
+
+  for (const [path, why] of Object.entries(PROTECTED_PATHS)) {
+    it(`has no ${path}.* of its own — ${why}`, () => {
+      const [parent, child] = path.split('.')
+      expect(overrides[parent]?.[child]).toBeUndefined()
+    })
+  }
+})