feat(bot): screenshot OCR pipeline + ack delay 120s

D fix: screenshots were silently dropped (empty body + OOB url).
- register xep_0066, capture msg['oob']['url'] when body empty
- also handle body-as-URL messages (some clients put URL in body)
- download from upload.yoin.fun, OCR via SenseNova (sensenova-6.7-flash-lite)
- inject OCR text as context into LLM call
- config at /home/hmo/.config/mofin/ocr_config.json (outside repo)
- replaces dead node122 GLM-OCR path (host unreachable)

A+B fix: ACK_DELAY 15s -> 120s. 15s fired on every normal LLM
cold-start (20-100s), now only signals genuine hangs.

scripts/test_image_pipeline.py

@@ -0,0 +1,23 @@
+import sys
+sys.argv = ['test', '--agent', 'zhiwei']
+# Prevent bot from actually connecting — just test the image functions
+src = open('/home/hmo/MoFin/deploy/bot/xmpp_agent_core.py').read()
+# Cut off at main entry to avoid starting the bot
+cut = src.find("if __name__ ==")
+if cut > 0:
+    src = src[:cut]
+ns = {}
+exec(compile(src, 'xmpp_agent_core.py', 'exec'), ns)
+
+url = "https://upload.yoin.fun/upload/d22cef590582300cc5580c722a19280054bf0d6a/brEbU8RxXwipU9VuhZqhhFOIAmQI4epG5dp5so6U/LBbTaPJdRfmzxjBg0uh21A.jpg"
+print("== _is_image_url ==", ns['_is_image_url'](url))
+print("== download ==")
+img = ns['_download_image'](url)
+print("bytes:", len(img) if img else None)
+if img:
+    print("== OCR ==")
+    ok, text = ns['_ocr_image'](img)
+    print("ok:", ok)
+    print("text:", text[:600])
+print("== full pipeline ==")
+print(ns['_process_image_message'](url)[:700])