feat(reader): Gitea client + config + board orchestrator

closes board-viewer-gitea-reader

- src/gitea.ts: HTTP client (getFile, getLatestCommitIso, rawUrl); DI'd fetch
- src/reader.ts: readBoard(client, repos) → TaskRecord[]
- src/config.ts: TOML config loader with board_viewer_repos whitelist
- 25 tests total (9 parser incl. 3 real-repo fixtures, 7 gitea, 5 reader, 4 config)
- emoji contract ⚪🔴🟡🔵🟢 (open/in_progress/paused/blocked/done)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/gitea.test.ts

@@ -0,0 +1,115 @@
+import { describe, expect, test, vi } from 'vitest';
+import { createGiteaClient } from '../src/gitea.ts';
+
+type MockFetch = ReturnType<typeof vi.fn>;
+
+function jsonResponse(body: unknown, status = 200): Response {
+  return new Response(JSON.stringify(body), {
+    status,
+    headers: { 'content-type': 'application/json' },
+  });
+}
+
+function makeClient(mockFetch: MockFetch) {
+  return createGiteaClient({
+    baseUrl: 'https://git.kzntsv.site',
+    token: 'test-token',
+    fetch: mockFetch as unknown as typeof fetch,
+  });
+}
+
+describe('GiteaClient.getFile', () => {
+  test('hits /api/v1/repos/<owner>/<repo>/contents/<path> with Authorization header', async () => {
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(
+      jsonResponse({
+        content: Buffer.from('hello world', 'utf8').toString('base64'),
+        encoding: 'base64',
+      }),
+    );
+    const client = makeClient(mockFetch);
+
+    await client.getFile('OpeItcLoc03', 'board-viewer', '.tasks/STATUS.md');
+
+    expect(mockFetch).toHaveBeenCalledTimes(1);
+    const [url, init] = mockFetch.mock.calls[0]!;
+    expect(url).toBe(
+      'https://git.kzntsv.site/api/v1/repos/OpeItcLoc03/board-viewer/contents/.tasks/STATUS.md',
+    );
+    expect((init as RequestInit).headers).toMatchObject({
+      Authorization: 'token test-token',
+    });
+  });
+
+  test('decodes base64 content and returns text', async () => {
+    const original = 'STATUS.md body\nwith newline.';
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(
+      jsonResponse({
+        content: Buffer.from(original, 'utf8').toString('base64'),
+        encoding: 'base64',
+      }),
+    );
+    const client = makeClient(mockFetch);
+
+    const result = await client.getFile('owner', 'repo', 'file.md');
+
+    expect(result).toBe(original);
+  });
+
+  test('returns null on 404 (file absent)', async () => {
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(
+      new Response('Not Found', { status: 404 }),
+    );
+    const client = makeClient(mockFetch);
+
+    const result = await client.getFile('owner', 'repo', 'missing.md');
+
+    expect(result).toBeNull();
+  });
+
+  test('throws on non-404 HTTP error (e.g. 500)', async () => {
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(
+      new Response('Server error', { status: 500 }),
+    );
+    const client = makeClient(mockFetch);
+
+    await expect(client.getFile('owner', 'repo', 'file.md')).rejects.toThrow(/500/);
+  });
+});
+
+describe('GiteaClient.getLatestCommitIso', () => {
+  test('returns commit date ISO string when commit exists', async () => {
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(
+      jsonResponse([
+        { commit: { author: { date: '2026-05-22T08:10:00Z' } } },
+      ]),
+    );
+    const client = makeClient(mockFetch);
+
+    const iso = await client.getLatestCommitIso('owner', 'repo', '.tasks/foo.md');
+
+    expect(iso).toBe('2026-05-22T08:10:00Z');
+    const [url] = mockFetch.mock.calls[0]!;
+    expect(url).toMatch(
+      /\/api\/v1\/repos\/owner\/repo\/commits\?path=\.tasks%2Ffoo\.md&limit=1/,
+    );
+  });
+
+  test('returns null when no commits touch the path', async () => {
+    const mockFetch: MockFetch = vi.fn().mockResolvedValue(jsonResponse([]));
+    const client = makeClient(mockFetch);
+
+    expect(await client.getLatestCommitIso('o', 'r', 'p.md')).toBeNull();
+  });
+});
+
+describe('GiteaClient.rawUrl', () => {
+  test('builds the raw URL for a file on the default branch', () => {
+    const client = makeClient(vi.fn());
+
+    const url = client.rawUrl('OpeItcLoc03', 'board-viewer', '.tasks/STATUS.md');
+
+    expect(url).toBe(
+      'https://git.kzntsv.site/OpeItcLoc03/board-viewer/raw/branch/master/.tasks/STATUS.md',
+    );
+  });
+});