refactor(options): own inventory reload scheduling

[blakinio]

Purpose

Continue merged PR #36 by removing the temporary global scheduleEvent/removeEvent interception from the Phase 0 compatibility adapter.

Delivered scope

• keep canonical showExpiryInInventory and legacy showExpiryInInvetory as one adapter-owned value;
• preserve canonical-precedence startup migration and dual settings writes;
• schedule inventory reload directly under adapter ownership;
• suppress raced stale callbacks and cancel only the preceding adapter-owned reload on rapid changes and during termination;
• preserve existing widget normalization and hidden unsupported controls;
• prove unrelated scheduling/removal is untouched;
• register the focused options Lua test as its own CTest target;
• document the hardening in the agent changelog after the shared-path lease was released.

Current-main reconciliation

PR #92 released the changelog lease, and PR #94 archived its separate W6 task. This branch was rebuilt on exact current main commit 4e09e32032e64831c30d6f7aeb31a2ebd4d4520a; its five changed paths do not overlap the #94 archive paths.

Validation

Final exact-head Windows CMake/CTest and repository required CI are pending on the rebuilt branch. Earlier runs were intentionally superseded when main advanced.

Safety

Legacy client Lua/test registration and agent documentation only. No authentication, protocol, renderer, Canary, server, proprietary asset or greenfield Rust runtime changes.

Task

OTC-20260729-options-phase1-native-migration