feat(ext/sw): GiteaHost.putBlob with Git Data API fallback

Same shape as GitHubHost (commit dc660c4) — Gitea v1 has /api/v1/
prefix, otherwise the endpoint shapes are identical. 2 new tests;
total 5 git-host tests.

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

extension/src/service-worker/__tests__/git-host.test.ts

@@ -1,5 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { GitHubHost } from '../github';
+import { GiteaHost } from '../gitea';
 import { BLOB_THRESHOLD_BYTES } from '../git-host';
 
 const REPO = 'alee/test-vault';
@@ -70,3 +71,55 @@ describe('GitHubHost.putBlob', () => {
     await expect(host.putBlob('attachments/big.bin', big, 'add big')).rejects.toThrow(/422|too big/);
   });
 });
+
+describe('GiteaHost.putBlob', () => {
+  beforeEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it('uses Contents API when content is at threshold', async () => {
+    const fetchMock = setupFetch();
+    // First fetch: GET existing file → 404 (create path)
+    fetchMock.mockResolvedValueOnce({ ok: false, status: 404, statusText: 'Not Found' } as Response);
+    // Second fetch: POST contents → 201 created
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 201, json: async () => ({}) } as Response);
+
+    const host = new GiteaHost('https://git.example.com', REPO, TOKEN);
+    const small = new Uint8Array(BLOB_THRESHOLD_BYTES);  // exactly threshold
+    await host.putBlob('attachments/abc.bin', small, 'add abc');
+
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(fetchMock.mock.calls[1][0]).toContain('/contents/');
+    expect(fetchMock.mock.calls[1][1]?.method).toBe('POST');
+  });
+
+  it('uses Git Data API fallback when content exceeds threshold', async () => {
+    const fetchMock = setupFetch();
+    // 1. POST /api/v1/.../git/blobs → blob SHA
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 201, json: async () => ({ sha: 'blobsha111' }) } as Response);
+    // 2. GET /api/v1/.../git/refs/heads/main → ref { object: { sha: 'commitsha' } }
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 200, json: async () => ({ object: { sha: 'commitsha111' } }) } as Response);
+    // 3. GET /api/v1/.../git/commits/commitsha111 → commit { tree: { sha: 'treesha' } }
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 200, json: async () => ({ tree: { sha: 'treesha111' } }) } as Response);
+    // 4. POST /api/v1/.../git/trees → new tree { sha: 'newtreesha' }
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 201, json: async () => ({ sha: 'newtreesha111' }) } as Response);
+    // 5. POST /api/v1/.../git/commits → new commit { sha: 'newcommitsha' }
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 201, json: async () => ({ sha: 'newcommitsha111' }) } as Response);
+    // 6. PATCH /api/v1/.../git/refs/heads/main → updated
+    fetchMock.mockResolvedValueOnce({ ok: true, status: 200, json: async () => ({}) } as Response);
+
+    const host = new GiteaHost('https://git.example.com', REPO, TOKEN);
+    const big = new Uint8Array(BLOB_THRESHOLD_BYTES + 1);  // one byte over
+    await host.putBlob('attachments/big.bin', big, 'add big');
+
+    expect(fetchMock).toHaveBeenCalledTimes(6);
+    // Gitea uses /api/v1/ prefix
+    expect(fetchMock.mock.calls[0][0]).toContain('/api/v1/repos/');
+    expect(fetchMock.mock.calls[0][0]).toContain('/git/blobs');
+    expect(fetchMock.mock.calls[1][0]).toContain('/git/refs/heads/');
+    expect(fetchMock.mock.calls[2][0]).toContain('/git/commits/');
+    expect(fetchMock.mock.calls[3][0]).toContain('/git/trees');
+    expect(fetchMock.mock.calls[4][0]).toContain('/git/commits');
+    expect(fetchMock.mock.calls[5][1]?.method).toBe('PATCH');
+  });
+});