fix(desktop): preserve snapshot attachment URLs (#1905)

Signed-off-by: Wes <wesbillman@users.noreply.github.com>
Co-authored-by: Pinky <44b8e82baa6e0e254e0208d68f335c283c94e7b78dd1fa10d5a49d3f13dd0435@sprout-oss.stage.blox.sqprod.co>

desktop/src/shared/ui/markdownFileCard.test.mjs

@@ -227,18 +227,23 @@ test("resolveSnapshotCard: uppercase .AGENT.JSON classifies as snapshot card", (
 
 // ── snapshot card thumbnails ─────────────────────────────────────────────────
 
-test("resolveSnapshotCard: .agent.png uses its own URL as thumb", () => {
+test("resolveSnapshotCard: keeps canonical PNG URL for actions", () => {
   const card = resolveSnapshotCard(
     { m: "image/png", size: 2048, filename: "bot.agent.png", x: SHA256 },
     PNG_URL,
     "",
   );
   assert.ok(card !== null);
-  // PNG attachment URL is rewritten by rewriteRelayUrl — just verify it's set
+  assert.equal(card.href, PNG_URL);
   assert.ok(
     card.thumb != null,
     "PNG card must have a thumb set from its own URL",
   );
+  assert.notEqual(
+    card.thumb,
+    card.href,
+    "only the display thumbnail may use the local media proxy",
+  );
 });
 
 test("resolveSnapshotCard: .agent.json without thumb field yields undefined thumb", () => {

desktop/src/shared/ui/markdownFileCard.ts

@@ -86,7 +86,7 @@ export function resolveSnapshotCard(
   const snapshotKind: "agent" | "team" = isJson || isPng ? "agent" : "team";
 
   return {
-    href: rewriteRelayUrl(href),
+    href,
     filename,
     size: entry.size,
     sha256,