chore: initial project setup with backend, frontend, CI/CD, and documentation

Add complete NexaFabric project structure including:
- FastAPI backend with SQLAlchemy models, JWT auth, RBAC, audit logging, and provider interfaces
- React + TypeScript frontend with Vite, Tailwind CSS, TanStack Query, and Zustand
- Docker Compose configuration for PostgreSQL, Redis, API, worker, frontend, and nginx
- GitHub Actions and GitLab CI workflows for testing, linting, building, and security scanning
- Environment

backend/app/schemas/domain.py

@@ -0,0 +1,183 @@
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, ConfigDict, EmailStr, Field
+
+
+class OrmModel(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+
+class TokenPair(BaseModel):
+    access_token: str
+    refresh_token: str
+    token_type: str = "bearer"
+
+
+class LoginRequest(BaseModel):
+    email: EmailStr
+    password: str
+
+
+class UserRead(OrmModel):
+    id: str
+    email: EmailStr
+    display_name: str
+    is_active: bool
+
+
+class ClusterCreate(BaseModel):
+    name: str
+    api_url: str
+    api_token: str = Field(min_length=8)
+    mode: str = "read_only"
+    verify_tls: bool = True
+
+
+class SecurityGroupCreate(BaseModel):
+    project_id: str | None = None
+    name: str
+    description: str | None = None
+
+
+class PolicyCreate(BaseModel):
+    project_id: str | None = None
+    name: str
+    enabled: bool = True
+    definition: dict[str, Any]
+
+
+class IpReservationCreate(BaseModel):
+    subnet_id: str
+    address: str
+    status: str = "reserved"
+    note: str | None = None
+
+
+class ClusterRead(OrmModel):
+    id: str
+    name: str
+    api_url: str
+    provider: str
+    mode: str
+    last_sync_at: datetime | None
+    last_sync_status: str | None
+    last_sync_error: str | None
+
+
+class NodeRead(OrmModel):
+    id: str
+    cluster_id: str
+    name: str
+    status: str
+    cpu_count: int
+    memory_mb: int
+
+
+class WorkloadRead(OrmModel):
+    id: str
+    cluster_id: str
+    node_id: str
+    project_id: str | None
+    external_id: str
+    name: str
+    kind: str
+    status: str
+    tags: list[str]
+
+
+class NetworkRead(OrmModel):
+    id: str
+    cluster_id: str
+    project_id: str | None
+    name: str
+    kind: str
+    vlan_id: int | None
+    mtu: int
+    gateway: str | None
+    dns: list[str]
+    dhcp_enabled: bool
+    tags: list[str]
+    description: str | None
+
+
+class SubnetRead(OrmModel):
+    id: str
+    network_id: str
+    cidr: str
+    gateway: str | None
+    dns: list[str]
+    dhcp_enabled: bool
+
+
+class IpAddressRead(OrmModel):
+    id: str
+    subnet_id: str
+    address: str
+    status: str
+    workload_id: str | None
+    note: str | None
+
+
+class TenantRead(OrmModel):
+    id: str
+    name: str
+    description: str | None
+
+
+class ProjectRead(OrmModel):
+    id: str
+    tenant_id: str
+    name: str
+    description: str | None
+
+
+class SecurityGroupRead(OrmModel):
+    id: str
+    project_id: str | None
+    name: str
+    description: str | None
+
+
+class PolicyRead(OrmModel):
+    id: str
+    project_id: str | None
+    name: str
+    version: int
+    enabled: bool
+    definition: dict[str, Any]
+    last_compiled: dict[str, Any] | None
+
+
+class FirewallPreview(BaseModel):
+    policy_id: str
+    dry_run: bool = True
+    generated_rules: list[dict[str, Any]]
+    warnings: list[str]
+    conflicts: list[str]
+
+
+class JobRead(OrmModel):
+    id: str
+    kind: str
+    status: str
+    progress: int
+    started_at: datetime | None
+    finished_at: datetime | None
+    logs: list[str]
+    error: str | None
+
+
+class AuditLogRead(OrmModel):
+    id: str
+    created_at: datetime
+    user_id: str | None
+    action: str
+    object_type: str
+    object_id: str | None
+    old_values: dict[str, Any] | None
+    new_values: dict[str, Any] | None
+    ip_address: str | None
+    user_agent: str | None
+    result: str
+    error_text: str | None