refactor: projectcain/vault35

[lesshonor]

Description

• Data-driven improvements (feature migration, encoder location, locking config)
• Add the missing all layout.
• Add encoder mapping to default keymap.
• There is now an RP2040 version of this keyboard which I plan to submit later—migrate this version to atmega32u4 in anticipation.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Per the PR Checklist:

• If the keyboard has multiple electrical/switch layouts:
  • include a LAYOUT_all which specifies all possible layout positions in the electrical matrix

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).