feat(district): District Interface Architecture v1

## Documentation
- District_Interface_Architecture_v1.md - повна архітектура District Layer
- District Space, Campus Map, Sub-DAOs, Portals
- Золотий трикутник: City → District → MicroDAO

## Database
- Migration 028: District rooms for Energyunion & GREENFOOD
- Portal rooms on City Square

## Frontend
- src/api/districts.ts - Districts API client
- DistrictDashboard.tsx - District Dashboard UI component

## Key concepts:
- District = MicroDAO type='district'
- District Lead Agent (Helion, ERP-Agent)
- Campus Map (2D)
- Sub-DAOs management
- District-to-City portals

docs/foundation/README.md

@@ -6,7 +6,7 @@
 
 ## Статус: ✅ FOUNDATION_UPDATE Complete
 
-**Всього файлів:** 19 (12 основних + 6 helpers + 1 patch)
+**Всього файлів:** 20 (13 основних + 6 helpers + 1 patch)
 
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@@ -24,7 +24,7 @@
 | 6 | [`microdao_Governance_And_Permissions_v1.md`](./microdao_Governance_And_Permissions_v1.md) | Ролі, ACL, governance MicroDAO/District |
 | 7 | [`DAARION_Identity_And_Access_Draft_v1.md`](./DAARION_Identity_And_Access_Draft_v1.md) | DAIS як IAM: DID, keys, wallets, trust levels |
 
-### Rooms та інтерфейси (8-12)
+### Rooms та інтерфейси (8-13)
 
 | № | Файл | Опис |
 |---|------|------|
@@ -33,6 +33,7 @@
 | 10 | [`City_Interface_Architecture_v1.md`](./City_Interface_Architecture_v1.md) | City Square, DARIO/DARIA, public rooms, portals |
 | 11 | [`Agents_Interface_Architecture_v1.md`](./Agents_Interface_Architecture_v1.md) | Agent-centric UI: primary/team agents, кабінети |
 | 12 | [`Nodes_Interface_Architecture_v1.md`](./Nodes_Interface_Architecture_v1.md) | Node dashboards, registration, health, DAGI Mesh |
+| 13 | [`District_Interface_Architecture_v1.md`](./District_Interface_Architecture_v1.md) | **NEW** District Layer: Campus Map, Sub-DAOs, Portals |
 
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