New LimitMonitorStore keyed by VID; each entry is a vector of
LimitDefinition (LIMITID + upper/lower deadband as arbitrary Items).
S2F45/F46 set, S2F47/F48 read. VLAACK validates each VID exists.
Four new SxFy in the catalog; codegen handles the nested
list-of-(VID, list-of-LimitDefinition) shape. LimitDefinition is
defined in store/limits.hpp and referenced as external_struct so the
data model and the message codecs share one type.
The actual "value crossed limit" detection + CEID emission is left to
the application's set_value path (E30 §6.21 leaves *how* the equipment
detects crossings up to the implementer).
COMPLIANCE.md: Limits Monitoring Additional capability flips ✅.
Tests: 80 cases / 465 assertions.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
