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/syntax_check.py

@@ -0,0 +1,8 @@
+import ast, sys
+src = open('/home/hmo/MoFin/deploy/bot/xmpp_agent_core.py').read()
+try:
+    ast.parse(src)
+    print('SYNTAX OK, lines:', len(src.splitlines()))
+except SyntaxError as e:
+    print('SYNTAX ERROR:', e)
+    sys.exit(1)