fix(markdown): correct image gallery rendering (#2894)

packages/vscode/src/DOCUMENTATION.md

@@ -45,6 +45,7 @@ The webview CSP permits `blob:` only for `worker-src` so shared UI parsers can r
 
 - `bridge-localfs-proxy-runtime.ts`
   - Local `/api/fs/read` and `/api/fs/raw` proxy helpers and shared proxy utility helpers.
+  - Returns an explicit unsupported response for server-owned Markdown image grants instead of forwarding them to OpenCode.
 
 - `bridge-proxy-runtime.ts`
   - Proxy route handlers (`api:proxy`, `api:session:message`) with injected helper dependencies.

packages/vscode/src/bridge-localfs-proxy-runtime.test.js

@@ -37,6 +37,14 @@ mock.module('vscode', () => ({
 const { tryHandleLocalFsProxy } = await import('./bridge-localfs-proxy-runtime');
 
 describe('bridge local fs proxy', () => {
+  it('does not forward server-owned Markdown image grant routes to OpenCode', async () => {
+    const response = await tryHandleLocalFsProxy('POST', '/api/openchamber/sessions/ses_1/markdown-image-grants');
+
+    expect(response?.status).toBe(501);
+    expect(Buffer.from(response?.bodyBase64 ?? '', 'base64').toString('utf8'))
+      .toContain('not supported in the VS Code runtime');
+  });
+
   it('returns a quiet optional stat miss for missing files', async () => {
     const response = await tryHandleLocalFsProxy('GET', '/api/fs/stat?path=%2Fmissing.ts&optional=true');
 

packages/vscode/src/bridge-localfs-proxy-runtime.ts

@@ -56,6 +56,9 @@ export const tryHandleLocalFsProxy = async (method: string, requestPath: string)
   }
 
   const fsProxyPath = normalizeFsProxyPath(parsed.pathname);
+  if (/^\/api\/openchamber\/sessions\/[^/]+\/markdown-image-grants$/.test(parsed.pathname)) {
+    return buildProxyJsonError(501, 'Markdown image grants are not supported in the VS Code runtime');
+  }
   if (!fsProxyPath) {
     return null;
   }