refactor(simulation): remove superseded skeleton String stubs (T-984)

D-229 makes BuildingPropertyTag the typed step-3 output that replaces the era/
society_profile/zone_palette String stubs on the skeleton. The tag + its derivation
(zone_type_id, flavor_ref, era/ConstructionEra, FloorExtent) all landed under T-957/
T-1006; this removes the now-dead stub fields they superseded:

- BlockSkeleton.era_modifications: Vec<EraModification> (era is per-footprint on
  BuildingPropertyTag.era now; era_cause retained as the block-level cause)
- QuarterSkeleton.society_profile: SocietyProfileRef (culture → tag.flavor_ref)
- QuarterSkeleton.zone_palette: Vec<ZoneDefinition> (zoning → tag.zone_type_id;
  distinct from FloorZone.zone_palette: ZonePalette, the real D-101 palette, kept)
- the now-orphaned `EraModification` and `SocietyProfileRef` String aliases

Kept: chunk_layout (real ChunkLayout / D-234 street network), z_band_zones (still
uses the ZoneDefinition alias), boundaries (separate stub, not D-229 scope).

cargo check + clippy -D warnings --all-targets clean; full server lib suite
1325 passed / 0 failed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.pql/changelog/ticket_history/2026-06.sql

@@ -9,3 +9,4 @@ Closed via board reconciliation (pql migration cleanup, 2026-06-06): the work
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-986', 'description', 'zone_type_id from (ZoningType + economic_role + seed) -> one of the 31 D-142 RON files. BuildingEntryClass from (zone_type x layout_mode x prosperity) incl. Commission/Organic credential fork + U-curve degrade. era from founding_age+prosperity+seed; initial_condition from prosperity_baseline (D-217).', 'zone_type_id from (ZoningType + economic_role + seed) -> one of the 31 D-142 RON files. BuildingEntryClass from (zone_type x layout_mode x prosperity) incl. Commission/Organic credential fork + U-curve degrade. era from founding_age+prosperity+seed; initial_condition from prosperity_baseline (D-217).
 
 Closed via board reconciliation (pql migration cleanup, 2026-06-06): zone_type_for / building_entry_class / construction_era / initial_condition all implemented + wired in server/src/atlas/skeleton_gen.rs; 31 D-142 zone-type RON files present. Implemented under T-957/T-1006; verified.', NULL, '2026-06-06 21:34:05', '2026-06-06 21:34:05', '2026-06-06 21:34:05', NULL, '3ec0178c5899bd68734ab0c06113fa49', 1) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-984', 'status', 'backlog', 'in_progress', NULL, '2026-06-06 21:35:56', '2026-06-06 21:35:56', '2026-06-06 21:35:56', NULL, 'd7710baccc79933eece6c4be27d0b1eb', 1) ON CONFLICT(hash) DO NOTHING;

.pql/changelog/tickets/2026-06.sql

@@ -171,3 +171,4 @@ Closed via board reconciliation (pql migration cleanup, 2026-06-06): the work
 INSERT INTO tickets (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-986', 'task', 'T-957', 'zone_type_id selection + BuildingEntryClass / era / initial_condition derivation', 'zone_type_id from (ZoningType + economic_role + seed) -> one of the 31 D-142 RON files. BuildingEntryClass from (zone_type x layout_mode x prosperity) incl. Commission/Organic credential fork + U-curve degrade. era from founding_age+prosperity+seed; initial_condition from prosperity_baseline (D-217).
 
 Closed via board reconciliation (pql migration cleanup, 2026-06-06): zone_type_for / building_entry_class / construction_era / initial_condition all implemented + wired in server/src/atlas/skeleton_gen.rs; 31 D-142 zone-type RON files present. Implemented under T-957/T-1006; verified.', 'done', 'high', NULL, 'server', 'D-229', '2026-05-25 19:11:15', '2026-06-06 21:34:05', NULL, 'eac3221ad05f8bfceee12ef66fe672d3', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-984', 'task', 'T-957', 'BuildingPropertyTag + FloorExtent/FloorHeightProfile structs; replace BlockSkeleton String stubs', 'Define BuildingPropertyTag (zone_type_id, footprint, extent, entry_class, flavor_ref, era/era_cause, initial_condition) + FloorExtent{base_floor,floor_count,FloorHeightProfile::{Uniform|Variable}}. Resolves Q-104: floor_at_voxel_z / voxel_range_for_floor pure fns. Replaces era/society_profile/zone_palette/chunk_layout String stubs in generator.rs.', 'in_progress', 'high', NULL, 'server', 'D-229', '2026-05-25 19:11:10', '2026-06-06 21:35:56', NULL, '8fb7fbe395fbeb0f735effbed6a4b76f', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);