feat: add catastro SSOT integration, 3DGS hybrid pipeline, casa demo v3

- SPEC: add User Story 0 (Property Setup via Catastro) as P1 entry
- SPEC: add catastro_data and catastro_imports tables to data model
- PLAN: add Phase 2A (Catastro Integration) with 8 tasks
- AGENTS.md: add 3 key decisions (Catastro SSOT, 3DGS hybrid, plan inputs)
- Demo v3: Spanish apartment (C/ Altabix 24, 3ºB, Elche), 7 rooms,
  upload panel for catastro/DXF, proper collisions on all doors

.specify/specs/001-interiorscan-mvp/SPEC.md

@@ -8,9 +8,22 @@
 
 ## User Scenarios & Testing
 
+### User Story 0 — Property Setup via Catastro (Priority: P1) 🎯 MVP Entry
+
+As a real estate agent, I enter a property address and InteriorScan fetches the building's exterior footprint from the Spanish Cadastro (INSPIRE WFS), so the 3D model starts with verified exterior walls before I upload any photos.
+
+**Why this priority**: The Catastro provides the SSOT for exterior geometry — wall outlines, building height, and number of floors. This eliminates manual exterior wall drawing and ensures dimensional accuracy. Interior walls come from photos or user-uploaded floor plans.
+
+**Independent Test**: Enter "C/ Altabix 24, Elche" → refcat is resolved → building polygon is displayed on a minimap → exterior walls are generated in the 3D scene.
+
+**Acceptance Scenarios**:
+1. **Given** I am creating a new project, **When** I type a Spanish address and submit, **Then** the system resolves it to a cadastral reference (refcat) and fetches the building footprint polygon from INSPIRE WFS.
+2. **Given** a building footprint is fetched, **When** the 3D scene initializes, **Then** exterior walls appear at the correct dimensions matching the Catastro polygon, with the correct number of floors.
+3. **Given** the Catastro lookup fails, **When** no polygon is found, **Then** the system falls back to manual wall drawing or DXF/SVG upload.
+
 ### User Story 1 — Upload & Process (Priority: P1) 🎯 MVP Core
 
-As a real estate agent, I upload 30-100 photos of a property and InteriorScan reconstructs the interior as a 3D walkthrough, so I can share a link with potential buyers who navigate it like a first-person game.
+As a real estate agent, I upload 30-100 photos of a property and InteriorScan reconstructs the interior as a 3D walkthrough, so I can share a link where potential buyers navigate it like a first-person game.
 
 **Why this priority**: Without reconstruction, nothing else matters. This is the core value proposition.
 

.specify/specs/001-interiorscan-mvp/data-model.md

@@ -148,6 +148,31 @@ export const processingJobs = pgTable('processing_jobs', {
   createdAt: timestamp('created_at').defaultNow().notNull(),
 });
 
+// ── Catastro Data ─────────────────────────────────────
+
+export const catastroData = pgTable('catastro_data', {
+  id: cuid2('id').primaryKey(),
+  projectId: cuid2('project_id').references(() => projects.id).notNull(),
+  refcat: text('refcat'),                          // 14-20 digit cadastral reference
+  addressNormalized: text('address_normalized'),    // Normalized address from Catastro
+  buildingFootprint: jsonb('building_footprint'),  // GeoJSON polygon from INSPIRE WFS
+  buildingHeight: text('building_height'),          // e.g., "12.5" meters
+  numberOfFloors: integer('number_of_floors'),      // From Catastro
+  floorArea: text('floor_area'),                    // m² from Catastro
+  gmlSource: text('gml_source'),                    // URL of the GML source file
+  fetchedAt: timestamp('fetched_at').defaultNow().notNull(),
+});
+
+export const catastroImports = pgTable('catastro_imports', {
+  id: cuid2('id').primaryKey(),
+  projectId: cuid2('project_id').references(() => projects.id).notNull(),
+  format: text('format').notNull(),   // 'dxf', 'svg', 'png', 'gml'
+  originalKey: text('original_key'),   // S3 key for uploaded file
+  parsedWalls: jsonb('parsed_walls'),  // Array of {x1, z1, x2, z2, height, thickness}
+  source: text('source').notNull(),    // 'catastro', 'upload', 'manual'
+  createdAt: timestamp('created_at').defaultNow().notNull(),
+});
+
 // ── Subscriptions ───────────────────────────────────
 
 export const subscriptions = pgTable('subscriptions', {

.specify/specs/001-interiorscan-mvp/plan.md

@@ -46,9 +46,22 @@ See `data-model.md` (separate document — same directory).
 
 ---
 
-## Phase 2: Photo Upload & Processing Pipeline (P1) 🎯 MVP Core
+## Phase 2: Property Setup & Photo Upload (P1) 🎯 MVP Core
 
-### 2A: Upload API
+### 2A: Catastro Integration
+
+- [ ] T007 Create `packages/catastro/` — Catastro client package
+- [ ] T008 Write failing test: address "C/ Altabix 24, Elche" → refcat resolved
+- [ ] T009 Implement OVK address search (SOAP/REST → refcat)
+- [ ] T010 Write failing test: refcat → building polygon GML from INSPIRE WFS
+- [ ] T011 Implement INSPIRE WFS client (GML → GeoJSON polygon)
+- [ ] T012 Implement GML polygon → wall segments converter (`{x1,z1,x2,z2,height,thickness}`)
+- [ ] T13 Write failing test: POST /api/v1/projects with address → catastro_data populated
+- [ ] T014 Implement project creation with Catastro lookup (address → refcat → footprint → walls)
+
+**Checkpoint**: Enter "C/ Altabix 24, Elche" → building polygon rendered in minimap → exterior walls in 3D scene.
+
+### 2B: Photo Upload API
 
 - [ ] T007 Write failing test: POST /api/v1/projects with photos returns 201 + project ID
 - [ ] T008 Implement project creation endpoint with Zod validation