feat(publish): add baijiahao and jianshu desktop adapters

Wires up Baijiahao (百家号) and Jianshu (简书) as first-class desktop
publish targets, with risk-control prompts surfaced in the runtime
controller and a normalized error message in publish records. Adds
external-link buttons in the publish management table, an asset
format conversion endpoint for cover image compatibility, and
reorders publish-status display priority so failures take precedence
over partial successes.

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

apps/admin-web/src/lib/cover-requirements.ts

@@ -27,10 +27,10 @@ const requirementCatalog: Record<string, Partial<PlatformCoverRequirement>> = {
   baijiahao: {
     required: true,
     supportMode: "native",
-    aspectRatio: 16 / 9,
-    aspectLabel: "16:9",
+    aspectRatio: 3 / 2,
+    aspectLabel: "3:2",
     outputWidth: 1200,
-    outputHeight: 675,
+    outputHeight: 800,
     priority: 100,
   },
 };