feat(sprint-4/etapa-5): modelo de privacidad RLS granular + UI de visibilidad

- SQL 010: tablas user_groups y group_memberships con RLS
- SQL 011: tabla process_access para acceso explícito a procesos
- SQL 012: función is_platform_admin() + políticas granulares (select/insert/update/delete) en processes
- types.ts: Process.ownerId (requerido)
- process-repo: fromRow mapea owner_id→ownerId; toRow preserva ownerId en updates; setShared() no-op documentado
- ImportPage: asigna ownerId: user.id al crear proceso
- LibraryPage: toggle Todos/Míos, OwnershipBadge (🔒/👤) en cada tarjeta, opción "Compartir con equipo" en menú de proceso propio con toast de confirmación
- Tests: ownerId: 'test-user' agregado a todos los fixtures de Process

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/features/report/components.test.tsx

@@ -229,7 +229,7 @@ describe('MethodologyFooter', () => {
       id: 'p1', name: 'Proceso Test', clientName: '',
       bpmnXml: '<def/>', currency: 'USD',
       overheadPercentage: 0.2, annualFrequency: 1000, analysisHorizonYears: 3, automationInvestment: 0,
-      createdAt: 0, updatedAt: 0, groupId: null, tags: [],
+      createdAt: 0, updatedAt: 0, groupId: null, tags: [], ownerId: 'test-user',
     }
     expect(() => render(<MethodologyFooter process={proc} />)).not.toThrow()
   })
@@ -239,7 +239,7 @@ describe('MethodologyFooter', () => {
       id: 'p1', name: 'Proc', clientName: '',
       bpmnXml: '', currency: 'USD',
       overheadPercentage: 0.25, annualFrequency: 1000, analysisHorizonYears: 3, automationInvestment: 0,
-      createdAt: 0, updatedAt: 0, groupId: null, tags: [],
+      createdAt: 0, updatedAt: 0, groupId: null, tags: [], ownerId: 'test-user',
     }
     render(<MethodologyFooter process={proc} />)
     const text = document.body.textContent ?? ''
@@ -251,7 +251,7 @@ describe('MethodologyFooter', () => {
       id: 'p1', name: 'Proc', clientName: '',
       bpmnXml: '', currency: 'USD',
       overheadPercentage: 0.2, annualFrequency: 1000, analysisHorizonYears: 3, automationInvestment: 0,
-      createdAt: 0, updatedAt: 0, groupId: null, tags: [],
+      createdAt: 0, updatedAt: 0, groupId: null, tags: [], ownerId: 'test-user',
     }
     render(<MethodologyFooter process={proc} />)
     const text = document.body.textContent ?? ''
@@ -338,6 +338,7 @@ describe('ReportPage — con datos completos', () => {
     updatedAt: Date.now() - 1000 * 60 * 30,
     groupId: null,
     tags: [],
+    ownerId: 'test-user',
   }
 
   const mockSimulation = {