fix: add curse amplification to applyEnemyDefenses (spec §6.3)

The curse debuff was stored on enemies via dot-runtime.ts but the
amplification was never applied to incoming damage. Added curse
magnitude check in applyEnemyDefenses (combat-tick.ts) that multiplies
incoming damage by (1 + magnitude) for each active curse effect.

- Curse amplification applied BEFORE dodge/barrier/armse defenses
- Multiple curse effects stack multiplicatively
- Non-curse effects (burn, freeze, etc.) are ignored for amplification

Also updated spire-combat-spec.md Known Gaps table to reflect:
- Melee defense bypass fixed (issue #285)
- Curse amplification now implemented (issue #286)

Added 9 regression tests in curse-amplification.test.ts.

All 957 tests pass (50 test files).

docs/circular-deps.txt

@@ -1,4 +1,4 @@
 # Circular Dependencies
-Generated: 2026-06-06T14:50:40.350Z
+Generated: 2026-06-06T15:33:46.661Z
 
 No circular dependencies found. ✅

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-06-06T14:50:38.455Z",
+    "generated": "2026-06-06T15:33:44.741Z",
     "description": "Import dependency graph for src/lib/game. Keys are files, values are arrays of files they import.",
     "usage": "To find what a file affects, search for its path in the VALUES. To find what a file depends on, look at its KEY entry."
   },

docs/project-structure.txt

@@ -215,6 +215,7 @@ Mana-Loop/
 │   │   │   │   ├── cross-module-helpers.ts
 │   │   │   │   ├── cross-module-lifecycle-consistency.test.ts
 │   │   │   │   ├── cross-module-prestige-discipline.test.ts
+│   │   │   │   ├── curse-amplification.test.ts
 │   │   │   │   ├── discipline-math.test.ts
 │   │   │   │   ├── discipline-prerequisites.test.ts
 │   │   │   │   ├── discipline-reactivate-bug.test.ts

docs/specs/spire-combat-spec.md

@@ -539,14 +539,14 @@ They are **in scope for the implementation this spec describes**:
 
 | Feature | Where Defined | Status | This Spec's Requirement |
 |---|---|---|---|
-| Enemy armor reduction | `EnemyState.armor`, `MODIFIER_CONFIG.armored` | **Implemented** (spells/DoTs only; melee bypasses — see issue #285) | Implement in `onDamageDealt` §5.2 |
-| Enemy barrier absorption | `EnemyState.barrier`, `MODIFIER_CONFIG.mage/shield` | **Implemented** (spells/DoTs only; melee bypasses — see issue #285) | Implement in `onDamageDealt` §5.2 |
-| Enemy dodge roll | `EnemyState.dodgeChance`, `MODIFIER_CONFIG.agile` | **Implemented** (spells/DoTs only; melee bypasses — see issue #285) | Implement in `onDamageDealt` §5.2 |
+| Enemy armor reduction | `EnemyState.armor`, `MODIFIER_CONFIG.armored` | **Implemented** — fixed in issue #285 (was bypassed for melee) | Implement in `onDamageDealt` §5.2 |
+| Enemy barrier absorption | `EnemyState.barrier`, `MODIFIER_CONFIG.mage/shield` | **Implemented** — fixed in issue #285 (was bypassed for melee) | Implement in `onDamageDealt` §5.2 |
+| Enemy dodge roll | `EnemyState.dodgeChance`, `MODIFIER_CONFIG.agile` | **Implemented** — fixed in issue #285 (was bypassed for melee) | Implement in `onDamageDealt` §5.2 |
 | Mage barrier recharge | `MODIFIER_CONFIG.mage.barrierRechargeRate` | Data-only | Tick in `onDamageDealt` §5.2 |
 | Guardian armor | `GuardianDef.armor` | Data-only | Add check to guardian pipeline §5.3 |
-| DoT / debuff system | Spell/enchantment type defs | **Implemented** — `dot-runtime.ts` complete and wired into combat tick | Verified working; curse amplification needs investigation (see issue #286) |
+| DoT / debuff system | Spell/enchantment type defs | **Implemented** — `dot-runtime.ts` complete and wired into combat tick; curse amplification added (issue #286) | Verified working |
 | Golemancy combat | Full golem data exists | Disconnected | Implement per §9 |
-| Sword melee attacks | Weapon type exists | **Partial** — meleeProgress exists but bypasses enemy defenses (see issue #285) | Add `meleeProgress` per §3.1 |
+| Sword melee attacks | Weapon type exists | **Implemented** — meleeProgress with enemy defense application (issue #285) | Add `meleeProgress` per §3.1 |
 | AoE target distribution | `SpellDefinition.aoe` flag | Partial | Implement per §3.2 |
 | `elemMasteryBonus` | Stub in `calcDamage` | Hardcoded `1` | Future — leave as `1` for now |
 | `guardianBonus` | Stub in `calcDamage` | Hardcoded `1` | Future — leave as `1` for now |