feat(hub): embed agent images via Feishu upload + release v0.0.36

Materialize markdown image refs on agent finish: fetch/read bytes, upload
im.v1.image, and render native card img elements so remote image URLs no
longer trip Feishu content-security. Stream masks image URLs mid-run;
card failure falls back to plain text plus standalone image messages.

Docs: clarify im:resource covers outbound Agent image send.

hub/src/feishu/client.ts

@@ -316,7 +316,8 @@ export async function sendCard(
       { msgType: "interactive", content: JSON.stringify(card) },
       options,
     );
-  } catch {
+  } catch (e) {
+    rt.logger.warn({ chatId, err: errorText(e) }, "sendCard failed");
     return null;
   }
 }
@@ -334,7 +335,7 @@ export async function patchCard(rt: FeishuRuntime, messageId: string, card: Reco
     });
     return true;
   } catch (e) {
-    rt.logger.warn({ messageId, err: e instanceof Error ? e.message : String(e) }, "patchCard failed");
+    rt.logger.warn({ messageId, err: errorText(e) }, "patchCard failed");
     return false;
   }
 }