fix(hub): strip card markdown images + prefer inline ![] over send_file

Feishu interactive markdown rejects ![](http...) without image_key
(error 230099 empty/missing imagekey). Always mask residual image md in
card builders; skip img tags with empty keys; skip inline-code examples;
fetch remote images with a browser UA and without env HTTP_PROXY.
Steer the agent: use ![alt](workspace-path) for 图文, send_file only for
downloadable attachments.

Release v0.0.37.

hub/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@paradigm/hub",
-  "version": "0.0.36",
+  "version": "0.0.37",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@paradigm/hub",
-      "version": "0.0.36",
+      "version": "0.0.37",
       "dependencies": {
         "@alicloud/credentials": "^2.4.5",
         "@alicloud/docmind-api20220711": "^1.4.15",