feat: Enhance interaction and inventory systems with new components and functionality

- Added BPC_UsableWorldObjectSystem for handling various interactable world objects with detailed manual implementation guide.
- Introduced BPC_ActiveItemSystem to manage quick slots and active item usage, including cycling and selection logic.
- Implemented BPC_DocumentArchiveSystem for managing collectible documents with read tracking and categorization.
- Developed BPC_JournalSystem for narrative entries with auto-adding features based on gameplay events.
- Created BPC_KeyItemSystem for key management with consumable and persistent key support.
- Enhanced BPC_FirearmSystem for ranged weapon mechanics, including hitscan and projectile firing.
- Updated BPC_MeleeSystem for melee combat with combo and blocking mechanics.
- Established BPC_ReloadSystem for managing weapon reloading processes, including partial reloads and state management.

docs/blueprints/03-interaction/19_BP_DoorActor.md

@@ -370,4 +370,137 @@ Interact_Implementation
 ### Anti-Cheat
 - Server validates player is within interaction range before opening door.
 - Server validates key item is in player inventory before unlocking.
-- Server validates barricade damage source.
+- Server validates barricade damage source.
+
+---
+
+## 14. Manual Implementation Guide
+
+### 14.1 Class Setup
+1. Create Blueprint Class: Parent = `Actor`, Name = `BP_DoorActor`
+2. Add components: `DoorRoot` (SceneComponent), `DoorFrame` (StaticMesh — static), `DoorMesh` (StaticMesh — rotates/slides), `InteractionCollision` (Box or Sphere)
+3. Implement Interfaces: `I_Interactable`, `I_Persistable`
+4. Set `Replicates` = true in Class Defaults
+
+### 14.2 Variable Defaults
+| Variable | Default |
+|----------|---------|
+| `CurrentState` | `Closed` |
+| `CurrentLockState` | `Unlocked` |
+| `CurrentBarricadeHealth` | `100.0` |
+| `AutoCloseDelay` | `3.0` (0 = never) |
+| `OpenAngle` | `90.0` |
+| `OpenSpeed` | `2.0` |
+| `CloseSpeed` | `1.5` |
+
+### 14.3 Function Node-by-Node
+
+#### `BeginPlay`
+```
+Event BeginPlay
+  → Cache OwningActor (Self)
+  → Get DoorMesh by tag/name → Cache DoorMeshComponent
+  → Spawn Audio Component → Cache DoorAudioComponent
+  → Apply DefaultState from DoorConfig:
+    Switch on DoorConfig.DefaultState:
+      Closed → (nothing, already closed)
+      Locked → Call LockDoor
+      Open → Call ForceSetState(Open) ← for save/load or pre-opened doors
+```
+
+#### `Interact_Implementation(Instigator: Actor)` — I_Interactable
+```
+Switch on CurrentState:
+  Closed → Call TryOpen(Instigator)
+  Open → Call TryClose(Instigator)
+  Locked → Call TryUnlockWithItem(Instigator)
+    Branch on result:
+      True → Call UnlockDoor → Call TryOpen(Instigator)
+      False → Call PlayLockedFeedback → Fire OnInteractionFailed
+  Barricaded → Call DamageBarricade(Instigator)
+    If attack breaks barricade → OnBarricadeBroken → SetState Closed
+  Opening/Closing → Return (ignored during animation)
+```
+
+#### `TryOpen(Instigator)` — **Must check HasAuthority() for MP**
+```
+  Branch: CurrentState != Closed → Return false
+  If DoorConfig.IsOneWay:
+    Check player side (dot product of door forward vs player forward)
+    If wrong side → Play locked feedback → Return false
+  SetWeaponState(Opening)
+  Fire OnDoorStateChanged
+  PlayOpenAnimation()  ← uses Timeline, not Timer
+```
+
+#### `PlayOpenAnimation` — **Key node setup:**
+```
+  Create Timeline (float track, 0→1 over OpenSpeed seconds)
+    Timeline Update pin:
+      → Get DoorMesh → Set Relative Rotation:
+        Lerp (Quat): startRotation to startRotation + Rotator(0, OpenAngle, 0) by Timeline Alpha
+    Timeline Finished pin:
+      → Call OnOpenComplete
+  Play Sound: AudioConfig.OpenSound at DoorMesh location via SS_AudioManager
+```
+
+#### `OnOpenComplete`
+```
+  Set CurrentState = Open
+  Fire OnDoorOpened(Instigator, bIsOpenFromFront)
+  If AutoCloseDelay > 0:
+    Set Timer by Event (AutoCloseDelay) → Call TryClose(Self)
+      Use "Self" as instigator for auto-close
+  Notify LinkedActors with "Open" event
+```
+
+#### `TryClose(Instigator)`
+```
+  Branch: CurrentState != Open → Return false
+  Set CurrentState = Closing
+  Clear AutoCloseTimer (if running — prevents auto-close during manual close)
+  Fire OnDoorStateChanged
+  PlayCloseAnimation()
+```
+
+#### `TryUnlockWithItem(Instigator)` → `Boolean`
+```
+  If CurrentLockState == KeyRequired:
+    Get RequiredItemTag from DoorConfig
+    Get Instigator → Get BPC_InventorySystem → Call HasItemQuantity(RequiredItemTag, 1)
+    If found:
+      If DoorConfig.RemoveItemOnUse:
+        BPC_InventorySystem.RemoveItemByTag(RequiredItemTag, 1)
+      Return true
+    Return false
+  If CurrentLockState == PuzzleLinked:
+    Get LinkedPuzzle → Call IsPuzzleSolved
+    Return result
+```
+
+#### `DamageBarricade(Instigator, DamageAmount)` 
+```
+  Branch: CurrentState != Barricaded → Return
+  CurrentBarricadeHealth -= DamageAmount
+  If CurrentBarricadeHealth <= 0:
+    Set CurrentBarricadeHealth = 0
+    Set CurrentState = Closed
+    Fire OnBarricadeBroken(Instigator)
+    Fire OnDoorStateChanged
+  Mark variable dirty (replication)
+```
+
+### 14.4 Blueprint Build Checklist
+- [ ] Create BP_DoorActor with DoorFrame + DoorMesh + InteractionCollision
+- [ ] Add all config variables (S_DoorConfig, S_DoorAudioConfig, LinkedActors)
+- [ ] Set DoorMesh mobility to Movable (for rotation during animation)
+- [ ] Implement I_Interactable with Interact_Implementation
+- [ ] Build TryOpen/TryClose with state validation
+- [ ] Create Timeline for door open/close animation (NOT Timer — Timeline for smooth interpolation)
+- [ ] Implement auto-close timer with reset on re-open
+- [ ] Build TryUnlockWithItem querying player inventory
+- [ ] Implement lock/barricade damage with health tracking
+- [ ] Add DoorAudioComponent for spatialized sounds
+- [ ] Set up LinkedActors — designer assigns in editor
+- [ ] Add networking: replicated CurrentState, Server_Interact RPC
+- [ ] Test: approach → interact → door opens → auto-closes → locked door → use key → unlocks