Uploads carry the name the file came with (#83)

An upload sends its file name next to the raw bytes, and the server keeps
it in a sidecar next to the content-addressed file. Both pickers caption
every tile and row with it, and an asset made there is named after the
file instead of "Texture" / "Font". Last upload of the same content wins.

The API's own set_error_handler ignores error_reporting(), so @-silenced
warnings still throw: a missing sidecar took the whole listing down with a
500. Existence is checked instead of suppressed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/core/http-store.test.ts

@@ -61,6 +61,20 @@ describe('HttpTextureStore', () => {
     expect(init?.headers).toEqual({ 'Content-Type': 'image/png' });
   });
 
+  it('sends the file name beside the route, and omits it when there is none', async () => {
+    const answer = JSON.stringify({ file: FILE, name: 'hero idle.png', width: 2, height: 3, bytes: 4 });
+    const bytes = new Blob([new Uint8Array(4)]);
+
+    let mock = stubFetch(answer, { status: 201 });
+    await new HttpTextureStore('/api').upload(bytes, 'image/png', 'hero idle.png');
+    // The body stays the raw image, so the name travels in the query – encoded, not as a path.
+    expect(mock.mock.calls[0]![0]).toBe('/api?r=textures&name=hero%20idle.png');
+
+    mock = stubFetch(answer, { status: 201 });
+    await new HttpTextureStore('/api').upload(bytes, 'image/png');
+    expect(mock.mock.calls[0]![0]).toBe('/api?r=textures');
+  });
+
   it('reports the nginx size limit as a size problem', async () => {
     stubFetch(NGINX_413, { status: 413, statusText: 'Request Entity Too Large' });
     const bytes = new Blob([new Uint8Array(8)]);

tests/core/texture-commands.test.ts

@@ -24,6 +24,19 @@ describe('CreateTextureCommand', () => {
     expect(findAsset(project, command.asset.id)?.name).toBe('Hero');
   });
 
+  it('keeps the caller’s name even though the upload result carries one of its own', () => {
+    const { project, stack } = makeProject();
+    // What `TextureStore.upload` actually answers: the file's original name and its byte count
+    // ride along. Copied wholesale they would land in the asset and rename it behind the caller.
+    const upload = { file: FILE, name: 'hero-idle.png', width: 64, height: 32, bytes: 900 };
+    const command = new CreateTextureCommand('Hero', upload);
+    stack.execute(command);
+
+    const asset = findAsset(project, command.asset.id);
+    expect(asset?.name).toBe('Hero');
+    expect(asset).not.toHaveProperty('bytes');
+  });
+
   it('rejects a file name the server cannot have produced – in execute, not in the constructor', () => {
     const { project, stack } = makeProject();
     const command = new CreateTextureCommand('Hero', { file: '../secrets.png', width: 1, height: 1 });