[WEB-6984] chore(i18n): gitignore auto-generated translation key types (#6784)

* [WEB-6984] chore(i18n): gitignore auto-generated translation key types

The file keys.generated.ts (4,800+ lines) is regenerated deterministically on every build via `pnpm run generate:types`. It should not be version-controlled, matching the existing pattern for .react-router/ generated types.

* [WEB-6984] fix(i18n): generate types before type-checking

Run generate:types before tsc in check:types script, matching the pattern React Router apps use in this repo. This fixes the chicken-and-egg problem where check:types runs before build in the turbo pipeline, but the generated keys.generated.ts (now gitignored) only existed after build.

.gitignore

@@ -113,6 +113,9 @@ build/
 .react-router/
 temp/
 
+# Auto-generated i18n translation key types (regenerated on build)
+packages/i18n/src/types/keys.generated.ts
+
 # Ignore any test results JSON files
 *test_results*.json
 apps/pi/tests/test_results.json

packages/i18n/package.json

@@ -25,7 +25,7 @@
     "sync:check": "npx tsx scripts/sync-check.ts",
     "check:sync": "npx tsx scripts/sync-check.ts --ci",
     "check:lint": "oxlint --type-aware -c ../../.oxlintrc.json .",
-    "check:types": "tsc --noEmit",
+    "check:types": "pnpm run generate:types && tsc --noEmit",
     "check:format": "oxfmt . --check",
     "fix:lint": "oxlint --type-aware --fix -c ../../.oxlintrc.json .",
     "fix:format": "oxfmt . --write",