fix: spire combat 11 high-severity discrepancies (issue #333)

D-01: Implement per-weapon cast progress (weaponCastProgress record)
D-04: Bypass Executioner/Berserker discipline specials for golem attacks
D-09: Fix lightning counter direction (lightning→water, not lightning→earth)
D-10: Add full composite element counters (blackflame/radiantflames ↔ frost/water/light/dark)
D-15: Fix Executioner to check per-enemy HP < 25% instead of floorHP ratio
D-20: Fix dodge formula to match spec (min(0.55, floor × 0.003), starts at 0)
D-22: Fix shield modifier to use flat HP pool instead of percentage barrier
D-23: Wire up applyMageBarrierRecharge in the damage pipeline
D-25: Move guardian regen from per-damage-event to once-per-tick
D-26: Add guardian armor reduction to the guardian defensive pipeline
D-31: Fix armor_corrode to be temporary (restore armor on effect expiry)
D-38: Implement AoE damage distribution across enemies

All 1069 tests pass. No files exceed 400 lines.

src/lib/game/stores/combat-descent-actions.ts

@@ -72,6 +72,7 @@ export function advanceRoomOrFloor(get: GetFn, set: SetFn): void {
         floorHP: newFloorHP,
         floorMaxHP: newFloorHP,
         castProgress: 0,
+        weaponCastProgress: {},
       });
       get().addActivityLog('floor_transition', `Descended to Floor ${newFloor}`);
     } else {
@@ -84,6 +85,7 @@ export function advanceRoomOrFloor(get: GetFn, set: SetFn): void {
         floorHP: newFloorHP,
         floorMaxHP: newFloorHP,
         castProgress: 0,
+        weaponCastProgress: {},
       });
     }
 
@@ -110,6 +112,7 @@ export function advanceRoomOrFloor(get: GetFn, set: SetFn): void {
         floorHP: newFloorHP,
         floorMaxHP: newFloorHP,
         castProgress: 0,
+        weaponCastProgress: {},
       });
       get().addActivityLog('floor_transition', `Ascending to Floor ${newFloor}`);
     } else {
@@ -122,6 +125,7 @@ export function advanceRoomOrFloor(get: GetFn, set: SetFn): void {
         floorHP: newFloorHP,
         floorMaxHP: newFloorHP,
         castProgress: 0,
+        weaponCastProgress: {},
       });
     }
 
@@ -216,7 +220,7 @@ export function onEnterRoomDescend(get: GetFn, set: SetFn): void {
 
   if (didReset) {
     const newRoom = generateSpireFloorState(s.currentFloor, s.currentRoomIndex, s.roomsPerFloor, s.runId);
-    set({ currentRoom: newRoom, castProgress: 0 });
+    set({ currentRoom: newRoom, castProgress: 0, weaponCastProgress: {} });
     get().addActivityLog('floor_transition',
       `Floor ${s.currentFloor} Room ${s.currentRoomIndex + 1} has reset — enemies respawned`);
 
@@ -263,6 +267,7 @@ export function createEnterSpireMode(get: GetFn, set: SetFn) {
       floorMaxHP: calcRoomHP(freshRoom),
       currentRoom: freshRoom,
       castProgress: 0,
+      weaponCastProgress: {},
       climbDirection: 'up',
       isDescending: false,
       clearedFloors: {},