feat: M0 monorepo skeleton with services, clients, deploy and CI

- api/openapi.yaml: contract with /healthz, /readyz, /api/v1/server-info
- services/api (Go): api with oapi-codegen strict server, goose migrations,
  readiness checks for Postgres/Redis; storage-agent stub with internal token
- services/recommender (Python, uv): FastAPI health/readiness/internal status,
  `pipu-rec serve` and `pipu-rec analyze` entrypoints
- packages: generated api-client, core (server URL + server check),
  i18n (ru/en + dictionary check), design-tokens (CSS vars + TS from tokens.json)
- apps/web: Vite + React shell showing server status, language switch
- apps/mobile: Expo (SDK 53) Android app with server connect screen
- deploy: Dockerfiles, compose (prod + dev), nginx template, install/update scripts
- .gitea/workflows: ci.yml and tag-based release.yml (images, signed APK, release)
- scripts/version.mjs: version and Android versionCode from git tag
- tests/fixtures/music/generate.sh: synthetic test library via ffmpeg
- docs: versionCode formula, OpenAPI 3.0.3, dev instructions in README

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/i18n/scripts/check.mjs

@@ -0,0 +1,37 @@
+// Проверяет словари: одинаковые ключи во всех языках и совпадение плейсхолдеров {{...}}.
+import { readdirSync, readFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const dir = join(dirname(fileURLToPath(import.meta.url)), '..', 'locales');
+const locales = readdirSync(dir);
+const flat = (obj, prefix = '') =>
+  Object.entries(obj).flatMap(([k, v]) =>
+    typeof v === 'object' ? flat(v, `${prefix}${k}.`) : [[`${prefix}${k}`, String(v)]],
+  );
+const placeholders = (s) => [...s.matchAll(/\{\{\s*(\w+)\s*\}\}/g)].map((m) => m[1]).sort().join(',');
+
+const data = {};
+for (const loc of locales) {
+  for (const file of readdirSync(join(dir, loc))) {
+    const ns = file.replace(/\.json$/, '');
+    for (const [k, v] of flat(JSON.parse(readFileSync(join(dir, loc, file), 'utf8')))) {
+      (data[`${ns}:${k}`] ??= {})[loc] = v;
+    }
+  }
+}
+
+const errors = [];
+for (const [key, byLoc] of Object.entries(data)) {
+  for (const loc of locales) {
+    if (!(loc in byLoc)) errors.push(`${loc}: отсутствует ключ ${key}`);
+  }
+  const sets = new Set(Object.values(byLoc).map(placeholders));
+  if (sets.size > 1) errors.push(`${key}: плейсхолдеры различаются между языками`);
+}
+
+if (errors.length) {
+  console.error(errors.join('\n'));
+  process.exit(1);
+}
+console.log(`i18n: ${Object.keys(data).length} ключей × ${locales.length} языка — ок`);