feat: port retail magic lifecycle and retained spell UI

Complete the retail cast-intent, target, component, enchantment, and busy-state paths; mount the DAT-authored spell bar, spellbook, component book, effects panels, and shared panel lifecycle; and add scoped input plus conformance coverage.

Co-Authored-By: Codex <noreply@openai.com>

AGENTS.md

@@ -108,12 +108,12 @@ movement queries.
 
 ## Current state
 
-**Currently working toward: M3 — Cast a spell. M2 — Kill a drudge LANDED 2026-07-15**:
-the live melee/missile loop covers weapon switching, target-facing, attack/damage/death, loot,
-inventory, and item giving. The M2/M3 projectile + DAT-effect foundation is automated through
-Step 9; single-client missiles/protection effects are user-gated. **Next:** reconcile F.4/L.1d's
-cast lifecycle against that foundation, then F.5 spellbook + active enchantments. **Carried:** final
-two-client portal/observer VFX gate, #145-residual, #116, R6/TS-42, and Track MP0. Detail below.
+**M3 — Cast a spell ACTIVE; automated implementation complete 2026-07-15.** Retail cast intent,
+component/target gates, live enchantment wire, Magic-scoped input, spell bar, spellbook, component
+book, effect indicators, shared main-panel switching, and positive/negative effects UI are implemented over the Step-9 projectile/DAT-effect
+foundation. **Next:** connected single-client magic UI/casting visual gate, then the final two-client
+portal-out/materialization observer gate. **Carried:** #145-residual, #116, R6/TS-42, Track MP0.
+Start magic work at `claude-memory/project_magic_ui_and_casting.md`; detailed state is below.
 
 For canonical state, read in this order:
 - [`docs/plans/2026-05-12-milestones.md`](docs/plans/2026-05-12-milestones.md) — milestone targets + freeze list per milestone