Refactor Gameplay Tags: Split DT_ProjectTags.csv into 11 per-category Data Tables

- Removed DT_ProjectTags.csv and migrated tags into separate Data Tables:
  - DT_Tags_Player.csv (35 tags)
  - DT_Tags_Interaction.csv (37 tags)
  - DT_Tags_Item.csv (28 tags)
  - DT_Tags_Narrative.csv (55 tags)
  - DT_Tags_AI.csv (24 tags)
  - DT_Tags_Save.csv (25 tags)
  - DT_Tags_Environment.csv (35 tags)
  - DT_Tags_Combat.csv (28 tags)
  - DT_Tags_State.csv (43 tags)
  - DT_Tags_Audio.csv (29 tags)
  - DT_Tags_Achievement.csv (22 tags)

- Updated INDEX.md to reflect new structure and deprecated DT_ProjectTags.csv.
- Enhanced documentation in 01-core-foundation.md regarding tag-driven architecture.

CONTEXT.md

@@ -44,6 +44,18 @@ Content/
     Input/                    # Enhanced Input assets (NEW)
       Actions/                # IA_* Input Action assets
       Contexts/               # IMC_* Input Mapping Context assets
+    DataTables/               # Gameplay Tag Data Tables (NEW — 11 per-category CSV files)
+      DT_Tags_Player.csv
+      DT_Tags_Interaction.csv
+      DT_Tags_Item.csv
+      DT_Tags_Narrative.csv
+      DT_Tags_AI.csv
+      DT_Tags_Save.csv
+      DT_Tags_Environment.csv
+      DT_Tags_Combat.csv
+      DT_Tags_State.csv
+      DT_Tags_Audio.csv
+      DT_Tags_Achievement.csv
     Achievements/
     Settings/
     State/                    # State Management assets (NEW)
@@ -110,7 +122,7 @@ docs/
    enhanced-input-system.md
    bpc-statemanager.md         # NEW — State Manager implementation checklist
 ```
-**Total: 135 numbered Blueprint files + 5 enums + 5 Data Assets + TEMPLATE.md + AUDIT_REPORT.md + INDEX.md + 11 developer docs + 8 architecture docs + 1 audit report = 166 files in 18 directory groups**
+**Total: 135 numbered Blueprint files + 5 enums + 5 Data Assets + 11 Data Table CSVs + TEMPLATE.md + AUDIT_REPORT.md + INDEX.md + 11 developer docs + 8 architecture docs + 1 audit report = 177 files in 19 directory groups**
 
 ## Naming Conventions
 | Prefix | Type |