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/core/src/server.test.ts

@@ -0,0 +1,59 @@
+import { createApiClient } from '@pipu/api-client';
+import { describe, expect, it } from 'vitest';
+
+import { checkServer, normalizeServerUrl } from './server';
+
+describe('normalizeServerUrl', () => {
+  it.each([
+    ['music.home.lan', 'https://music.home.lan'],
+    ['  https://music.home.lan/  ', 'https://music.home.lan'],
+    ['http://192.168.1.10:8080', 'http://192.168.1.10:8080'],
+    ['https://home.lan/pipu//', 'https://home.lan/pipu'],
+  ])('%s → %s', (input, expected) => {
+    expect(normalizeServerUrl(input)).toBe(expected);
+  });
+
+  it.each(['', '   ', 'ftp://music.home.lan', 'https://'])('rejects %j', (input) => {
+    expect(normalizeServerUrl(input)).toBeNull();
+  });
+});
+
+const info = {
+  name: 'pipu-music',
+  version: '0.1.0',
+  api_version: 'v1',
+  supported_locales: ['ru', 'en'],
+  min_android_version_code: 100,
+};
+
+function clientReturning(response: () => Response | Promise<Response>) {
+  return createApiClient({ baseUrl: 'https://music.test', fetch: async () => response() });
+}
+
+const json = (body: unknown, status = 200) =>
+  new Response(JSON.stringify(body), { status, headers: { 'Content-Type': 'application/json' } });
+
+describe('checkServer', () => {
+  it('reports ok for a compatible server', async () => {
+    await expect(checkServer(clientReturning(() => json(info)), 100)).resolves.toEqual({ status: 'ok', info });
+  });
+
+  it('reports unsupported_app when the app is too old', async () => {
+    const res = await checkServer(clientReturning(() => json(info)), 99);
+    expect(res.status).toBe('unsupported_app');
+  });
+
+  it('reports offline on network errors', async () => {
+    const res = await checkServer(
+      clientReturning(() => {
+        throw new TypeError('Failed to fetch');
+      }),
+    );
+    expect(res).toEqual({ status: 'offline', error: 'Failed to fetch' });
+  });
+
+  it('reports offline with the problem code on API errors', async () => {
+    const res = await checkServer(clientReturning(() => json({ status: 500, code: 'common.internal' }, 500)));
+    expect(res).toEqual({ status: 'offline', error: 'common.internal' });
+  });
+});