MSM ACCESS PERUMAHAN WG v2.4.1 VISITOR FIX

FIXED
- Operator visitor form: fixed v2.4 control overlap (all nine visitor fields were created at identical Y coordinates).
- Visitor form now uses a 3-column x 3-row layout above the existing registration buttons.
- Existing visitor engine retained: unknown visitor card event at an IN gate populates token; manual token also falls back to primary configured IN gate.
- Existing ACB-W1/W2/W4 dynamic channel core retained unchanged.

ARCHITECTURE
- Added docs/SDK_ARCHITECTURE_v1.txt for universal ACB SDK design (W1/W2/W4 + barrier/tripod/flap/swing/door profiles).

VALIDATION
- Source compile is performed for Windows amd64 and x86.
- Physical ACB write/read-back and relay operation still require field test on the actual controller.
