docs(objective): p3-25 Phase-0 culture_stored landed; clarify unit-XP deferral

Mark CityView.culture_stored done (04763a387) — the last clean Phase-0 projection
gap. Note UnitView.experience already projects bench MapUnit XP; the deferred item
is the live-unit XP store (Phase 1).

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

.project/objectives/p3-25-rail1-city-model-unify-headless-view-completeness.md

@@ -146,8 +146,14 @@ Phase-0 increments landed (each `view_json`-additive, mc-player-api green):
   `pending_promotion`. Added `UnitPostureView` (embarked/deployed/stealth/ambush/field_aura/
   fire_arrows/pursuing/shield_wall/braced/rage/war_cry) + `formation_id`, own-units-only.
 - [x] **Golden Age → HUD** (f64ef19ba) — `ResourceView.golden_age_active/turns`.
-- Deferred (real bench-model gaps, → Phase 1 SOT flip, not fabricated): unit `experience`/XP,
-  per-city `culture_stored`, per-building `building_queues`, `placed_buildings` tile positions.
+- [x] **Per-city culture meter** (c563ca194) — `CityView.culture_stored` projected from
+  `PlayerState.culture_pool.city(c_idx)` (the accumulator `mc-turn::process_culture` ticks for
+  border expansion); 0.0 for a city with no pool entry. `projection_surfaces_city_culture_stored`;
+  mc-player-api lib 142/0. **Closes the last clean Phase-0 projection gap.**
+- Deferred (real bench-model gaps, → Phase 1 SOT flip, not fabricated): unit `experience`/XP
+  (note: `UnitView.experience` IS projected for the bench `MapUnit.experience`, projection.rs:371 —
+  the live-unit XP store is the Phase-1 item), per-building `building_queues`, `placed_buildings`
+  tile positions.
 
 ## Notes