V1: Design access module placement and cable routing

[mastertape]

Roadmap reference: docs/roadmap/dhl-paketkasten-retrofit-v1.md

Study how keypad, RFID and optional fingerprint modules can be mounted and wired on the DHL parcel box retrofit.

Acceptance criteria:

• Candidate mounting positions are documented with photos/sketches.
• Existing lock opening/front cut-out reuse is evaluated.
• Cover plate or adapter plate need is described.
• Door-to-body cable routing is sketched.
• Cable fatigue and weather exposure risks are listed.
• Wiegand, relay, UART or standalone module interfaces are identified for the actual modules.
• Replacement of the access module without redesigning the whole door is considered.

Reference:

• docs/hardware/wiegand-access-port.md