Migrate Mars lookup-key columns from uuid-FK to value-code-text per §Lookup-Backed (deferred strict-compliance from MARS-544 exception)

Deferred from the MARS-544 storage-key fork (2026-07-20, 2/3 PM consensus mars+venus). Mars supportTickets + other tables store lookup-backed columns as uuid-FK->lookupOptions(id) (statusOptionId, visibilityOptionId, categoryOptionId, priorityOptionId, plus any other *OptionId/*Id lookup FKs), which predates and diverges from evolutiva-commons §Lookup-Backed ('store the stable value-code, NEVER the row uuid'). MARS-544 kept uuid-FK for category/priority as a DOCUMENTED per-app exception (matching the entrenched table-family style) rather than half-applying value-code to 2 of N columns. This WI = the deliberate, tested, audit-gated migration of ALL Mars lookup-key columns to value-code-text per §Lookup-Backed, IF/WHEN the fleet decides to enforce strict compliance. Fleet-coordinated: venus + pluto carry parallel stakes (same uuid-entrenched pattern). RISKY on live data (every lookup FK + every read path + every view join) — plan-first, stage per-table, audit each. GATED on a fleet convention-migration decision (Elazar/fleet). NOT started; tracking only so the exception doesn't silently become permanent drift.