fix(docs): restore corrupted reference repos (eg4-bridge, lux-protocol)

Commit ab01c19 ('sync all local changes') accidentally overwrote ~100 files
in the vendored reference repos with unrelated binary garbage (git tree
objects, OpenClaw exec-approval socket JSON, an MIT license, process dumps,
a lux-mon config example). The .rs source files, .md specs, and .py helpers
were all unrecoverable from HEAD.

Restored both directories from the clean initial commit 64b587e, which
contained the intact upstream mirrors (jaredmauch/eg4-bridge and the
lux-protocol spec). Verified:
- all .rs files are valid Rust text again
- PROTOCOL.md / REGISTERS.md / DESIGN.md / README.md restored
- .png files have valid PNG magic
- the docs we actively use (EG4-18KPV-12LV-Modbus-Protocol.txt,
  LXP_REGISTERS.txt) were already identical and unchanged

Author: jmewing