Add Planar Capture System implementation checklist and developer reference

- Created a comprehensive implementation checklist for the Planar Capture System (Systems 136-147) detailing tasks across multiple phases including C++ core, material foundation, Blueprint actors, data assets, integration, and performance testing.
- Added a developer reference document outlining the architecture, data flow, state machine, budget enforcement, render target pooling, horror features, integration points, multiplayer networking, performance characteristics, debugging methods, and build order for the capture systems.
- Introduced examples of capture surface usage in the Project Void horror game, including specific implementations for mirrors, monitors, portals, and fake windows, along with a checklist for integration tasks.

CONTEXT.md

@@ -68,6 +68,22 @@ Content/
       S_ActionPermissionResult.uasset # Permission result struct
       DA_StateGatingTable.uasset      # All gating rules (37 action rules)
       BPC_StateManager.uasset         # Central state authority component
+    Capture/                  # Planar Capture assets (NEW — Phase 17)
+      BP_Mirror.uasset                # Standard mirror surface
+      BP_Portal.uasset                # Portal surface with linked target
+      BP_Monitor.uasset               # Security camera monitor
+      BP_HorrorMirror.uasset          # Horror mirror with wrong reflection
+      BP_FakeWindow.uasset            # Architectural fake window
+      M_CaptureSurface_Master.uasset  # Master unlit material (9-layer)
+      MPC_CaptureSurface.uasset       # Global MPC (10 scalar params)
+      DA_PlanarCaptureProfile.uasset  # Per-surface capture config
+      MI_Mirror_Clean.uasset          # Material instances
+      MI_Mirror_Dirty.uasset
+      MI_Mirror_Steam.uasset
+      MI_Mirror_Horror.uasset
+      MI_Portal_Standard.uasset
+      MI_Monitor_Security.uasset
+      MI_FakeWindow_Interior.uasset
 
 docs/
   blueprints/
@@ -83,13 +99,14 @@ docs/
     07-narrative/              # Narrative, Dialogue, Objective & Choice (11 files, 58-68)
     08-weapons/                # Weapon, Equipment & Damage (11 files, 69-79)
     09-ai/                     # AI, Perception & Encounters (9 files, 80-88)
-    10-adaptive/               # Adaptive Environment, Atmosphere & Scare (15 files, 89-101, 132-133)
-    11-meta/                   # Achievements, Progression & Meta (2 files, 102-103)
-    12-settings/               # Settings, Accessibility & Platform (2 files, 104-105)
-    13-polish/                 # Tutorial, Loading, Credits, Debug (9 files, 106-114)
-    14-data-assets/            # Data Asset definitions (16 files, 115-127, 129, 134-135)
-    15-input/                  # Enhanced Input System (1 file, 128)
-    16-state/                  # State Management (2 files, 130-131)
+     10-adaptive/               # Adaptive Environment, Atmosphere & Scare (15 files, 89-101, 132-133)
+     11-meta/                   # Achievements, Progression & Meta (2 files, 102-103)
+     12-settings/               # Settings, Accessibility & Platform (2 files, 104-105)
+     13-polish/                 # Tutorial, Loading, Credits, Debug (9 files, 106-114)
+     14-data-assets/            # Data Asset definitions (16 files, 115-127, 129, 134-135)
+     15-input/                  # Enhanced Input System (1 file, 128)
+     16-state/                  # State Management (2 files, 130-131)
+     17-capture/                # Planar Capture System (12 files, 136-147)
   developer/                  # Developer Reference Docs (NEW)
     INDEX.md                   # Master developer docs index (12 docs)
     architecture-overview.md   # Framework-wide architecture walkthrough
@@ -106,16 +123,17 @@ docs/
     09-ai-systems.md           # AI, perception & encounters explained
     10-adaptive-systems.md     # Adaptive environment & atmosphere explained
     11-16-systems.md           # Meta, Settings, Polish, Data Assets, Input, State explained
-  architecture/                # Architecture & Design Documents (8 files)
-   bpc-statemanager.md         # BPC_StateManager full spec + Chooser Table Audit
-   metasounds-audio-system.md  # MetaSounds audio architecture (mix buses, room zones, settings)
-   animation-catalog.md        # Animation requirements for all 135 systems
-   sound-catalog.md            # Sound/audio requirements for all 135 systems
-   enhanced-input-system.md    # Enhanced Input System architecture
-   hud-overview.md             # HUD system architecture — 14 widgets, wiring, integration points
-   multiplayer-networking.md   # Multiplayer networking architecture — authority model, RPCs, prediction
-   blueprint-limitations-workarounds.md  # UE5 C++-only functions + 100% Blueprint workarounds (NEW)
-   CLEAN_SLATE_PLAN.md         # Clean slate refactoring plan
+   architecture/                # Architecture & Design Documents (9 files)
+    bpc-statemanager.md         # BPC_StateManager full spec + Chooser Table Audit
+    metasounds-audio-system.md  # MetaSounds audio architecture (mix buses, room zones, settings)
+    animation-catalog.md        # Animation requirements for all 135 systems
+    sound-catalog.md            # Sound/audio requirements for all 135 systems
+    enhanced-input-system.md    # Enhanced Input System architecture
+    hud-overview.md             # HUD system architecture — 14 widgets, wiring, integration points
+    multiplayer-networking.md   # Multiplayer networking architecture — authority model, RPCs, prediction
+    blueprint-limitations-workarounds.md  # UE5 C++-only functions + 100% Blueprint workarounds (NEW)
+    planar-capture-system.md    # Planar Capture System — mirrors, portals, monitors, horror surfaces (Phase 17)
+    CLEAN_SLATE_PLAN.md         # Clean slate refactoring plan
  reports/                     # Condensed audit reports
    blueprint_condensed_summary.md  # ASK agent audit of all 129 files
  checklists/                  # Implementation checklists
@@ -123,7 +141,7 @@ docs/
    enhanced-input-system.md
    bpc-statemanager.md         # NEW — State Manager implementation checklist
 ```
-**Total: 135 numbered Blueprint files + 5 enums + 5 Data Assets + 11 Data Table CSVs + TEMPLATE.md + AUDIT_REPORT.md + INDEX.md + 12 developer docs + 8 architecture docs + 1 audit report = 178 files in 19 directory groups**
+**Total: 147 numbered Blueprint files + 5 enums + 5 Data Assets + 11 Data Table CSVs + TEMPLATE.md + AUDIT_REPORT.md + INDEX.md + 13 developer docs + 9 architecture docs + 1 audit report = 192 files in 20 directory groups**
 
 ## Naming Conventions
 | Prefix | Type |
@@ -180,6 +198,7 @@ docs/
 - **Phase 14:** State Management (BPC_StateManager + 4 enums + 3 structs + DA_StateGatingTable — 130, 131)
 - **Phase 15:** MetaSounds Audio (SS_AudioManager + BP_RoomAudioZone + DA_AudioSettings + DA_RoomAcousticPreset — 132-135)
 - **Phase 16:** Multiplayer Networking — All systems updated with `HasAuthority()` gates, `Server_` RPCs, `RepNotify` handlers, and client prediction patterns. See [`docs/architecture/multiplayer-networking.md`](docs/architecture/multiplayer-networking.md).
+- **Phase 17:** Planar Capture System — Mirrors, portals, monitors, horror surfaces. C++ core (136-138) + Blueprint actors (139-143) + Material/MPC (144-145) + Data Assets (146-147). See [`docs/architecture/planar-capture-system.md`](docs/architecture/planar-capture-system.md).
 
 ## Key Communication Rules
 1. Gameplay Tags + Subsystem lookup (global, decoupled)
@@ -235,4 +254,4 @@ No PR is accepted without these files being current. This ensures the animator,
 - **Phase 8-13:** COMPLETE — AUDIT_REPORT updated, CONTEXT.md updated, verification, final commit
 - **Phase 14-15:** COMPLETE — State Management (130-131) + MetaSounds Audio (132-135) blueprint specs created
 - **Phase 16:** IN PROGRESS — Multiplayer Networking: all 135 blueprint specs being updated with replication stubs, RPC definitions, and server-authoritative patterns. Developer docs updated. Architecture doc created at [`docs/architecture/multiplayer-networking.md`](docs/architecture/multiplayer-networking.md)
-- **Remaining:** Cross-reference pass across all 135 files; deprecated BPC_AudioAtmosphereController (95) references to update
+- **Remaining:** Cross-reference pass across all 147 files; deprecated BPC_AudioAtmosphereController (95) references to update; Planar Capture System (Phase 17) C++ written, blueprint specs created, pending UE5 editor compile and BP child creation