Sprinkle pca-re/docs/manuals/ citations into the four files that map
hardest to user-visible panel behavior, so a reader chasing "why is
this byte 0x03 here" lands on the right manual chapter directly from
the source.
models.SecurityMode
Per-value comments summarising what each arming mode means at the
keypad (entry/exit delays, which zones it arms, when to use it).
Points at the Owner's Manual SECURITY_SYSTEM_OPERATION chapter where
these semantics are spelled out for end users.
models.ZoneType
Class docstring now points at the Installation Manual SETUP ZONES
table where each numeric byte value is named -- the byte values and
short names we chose match that table one-for-one, so a reader can
cross-walk the v1 ZoneStatus byte to "PERIMETER" / "AWAY INT" / etc.
by row.
events.py
Module docstring adds Cross-references to APPENDIX A (Contact ID
reporting format) and APPENDIX B (digital communicator code sheet)
in the Installation Manual -- the central-station codes a panel
transmits for each AlarmKind correspond directly to those tables.
commands.py
Module docstring points at the Owner's Manual CONTROL, Scene Commands,
and SECURITY SYSTEM OPERATION chapters so the reader can tie each
enuUnitCommand byte to the user-facing keypad path that triggers it.
No code changes; all 387 tests still pass.
