docs(2.1.2): replace datasource screenshots from demo (rule-engine datasource)

Capture each connector form via 新增 -> type card on demo.fluxmq.com; update
BEFORE overview (vs/datasimg), DATABASE driver section (img2), LOG (img_1),
and gzyq/action bridge examples aligned with refreshed source forms.

Made-with: Cursor

Author: 1ssqq1lxr