refactor(renderer): configure the Markdown image renderer at startup

renderMarkdown ran the marked configuration on every call and leaned on a
module-level flag to make that cheap. It belongs next to the custom element
registration, which already runs once, before anything renders.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/src/renderer/src/main.js

@@ -7,6 +7,7 @@ import { commitInitialData, fetchInitialData } from './data.js';
 import { noteSessionUpdated, sessionLiveState } from './session-live.mjs';
 import { createGlobalDataRefreshCoordinator } from './session-global-refresh.mjs';
 import { registerSessionImageElement } from './session-image-element.js';
+import { configureMarkdownImages } from './markdown-image-renderer.js';
 import { installFileReferenceHandler } from './file-references.mjs';
 
 // Import shared renderer CSS globally
@@ -17,6 +18,8 @@ import '../styles/list.css';
 import '../styles/detail.css';
 
 registerSessionImageElement();
+// marked is loaded globally via CDN in index.html, ahead of this module.
+configureMarkdownImages(window.marked);
 
 const app = createApp(App);
 

app/src/renderer/src/utils.js

@@ -2,7 +2,6 @@
 // Pure helpers with no side-effects on global state (except formatProjectLabel which reads store).
 
 import { state } from './store.js';
-import { configureMarkdownImages } from './markdown-image-renderer.js';
 import { markFileReferences, mayContainFileReference } from './file-references.mjs';
 
 // --- Time / formatting ---
@@ -96,8 +95,7 @@ export function highlightTextNodes(rootEl, query) {
 
 export function renderMarkdown(text, opts = {}) {
   if (text == null) return '';
-  // marked is loaded globally via CDN in index.html
-  configureMarkdownImages(window.marked);
+  // marked is loaded globally via CDN in index.html and configured at startup.
   const html = sanitizeMarkdown(window.marked.parse(text));
   const cls = opts.variant === 'msg' ? 'markdown-msg'
             : opts.variant === 'compact' ? 'markdown-compact'