feat: add stage 0 foundation

backend/apps/__init__.py

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+

backend/apps/accounts/__init__.py

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+

backend/apps/accounts/api.py

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+from ninja import Router
+
+router = Router(tags=["accounts"])

backend/apps/accounts/apps.py

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+from django.apps import AppConfig
+
+
+class AccountsConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.accounts"

backend/apps/accounts/management/__init__.py

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+

backend/apps/accounts/management/commands/__init__.py

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+

backend/apps/accounts/management/commands/seed_permissions.py

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+from django.contrib.auth.models import Group, Permission
+from django.contrib.contenttypes.models import ContentType
+from django.core.management.base import BaseCommand
+
+from apps.accounts.permissions import DEFAULT_GROUPS, PERMISSIONS
+
+
+class Command(BaseCommand):
+    help = "Seed MVP permissions and default user groups."
+
+    def handle(self, *args, **options):
+        content_type, _ = ContentType.objects.get_or_create(
+            app_label="system",
+            model="platformpermission",
+        )
+
+        permissions_by_codename: dict[str, Permission] = {}
+        for spec in PERMISSIONS:
+            permission, _ = Permission.objects.get_or_create(
+                content_type=content_type,
+                codename=spec.codename,
+                defaults={"name": spec.name},
+            )
+            if permission.name != spec.name:
+                permission.name = spec.name
+                permission.save(update_fields=["name"])
+            permissions_by_codename[spec.codename] = permission
+
+        for group_name, codenames in DEFAULT_GROUPS.items():
+            group, _ = Group.objects.get_or_create(name=group_name)
+            group.permissions.set(permissions_by_codename[codename] for codename in codenames)
+
+        self.stdout.write(self.style.SUCCESS("Seeded permissions and groups."))

backend/apps/accounts/models.py

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+# Use Django's built-in User, Group, and Permission models for MVP RBAC.

backend/apps/accounts/permissions.py

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+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class PermissionSpec:
+    codename: str
+    name: str
+
+
+PERMISSIONS: tuple[PermissionSpec, ...] = (
+    PermissionSpec("ticket.view", "View tickets"),
+    PermissionSpec("ticket.create", "Create tickets"),
+    PermissionSpec("ticket.edit", "Edit tickets"),
+    PermissionSpec("ticket.export", "Export tickets"),
+    PermissionSpec("ticket.assign", "Assign tickets"),
+    PermissionSpec("ticket.close", "Close tickets"),
+    PermissionSpec("knowledge.view", "View knowledge"),
+    PermissionSpec("knowledge.manage", "Manage knowledge"),
+    PermissionSpec("solution.view", "View solutions"),
+    PermissionSpec("solution.manage", "Manage solutions"),
+    PermissionSpec("agent.use", "Use Agents"),
+    PermissionSpec("agent.manage", "Manage Agents"),
+    PermissionSpec("model.manage", "Manage model configs"),
+    PermissionSpec("tool.manage", "Manage MCP tools"),
+    PermissionSpec("audit.view", "View audit logs"),
+    PermissionSpec("system.manage", "Manage system settings"),
+)
+
+DEFAULT_GROUPS: dict[str, tuple[str, ...]] = {
+    "System Admin": tuple(permission.codename for permission in PERMISSIONS),
+    "Knowledge Admin": (
+        "ticket.view",
+        "knowledge.view",
+        "knowledge.manage",
+        "solution.view",
+        "solution.manage",
+        "agent.use",
+    ),
+    "Support Engineer": (
+        "ticket.view",
+        "ticket.create",
+        "ticket.edit",
+        "ticket.assign",
+        "ticket.close",
+        "knowledge.view",
+        "solution.view",
+        "agent.use",
+    ),
+    "Requester": (
+        "ticket.view",
+        "ticket.create",
+        "knowledge.view",
+        "solution.view",
+    ),
+    "Auditor": (
+        "ticket.view",
+        "knowledge.view",
+        "solution.view",
+        "audit.view",
+    ),
+}

backend/apps/accounts/schemas.py

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+

backend/apps/accounts/tests/__init__.py

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+

backend/apps/accounts/tests/test_permissions_seed.py

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+from django.contrib.auth.models import Group, Permission
+from django.core.management import call_command
+
+from apps.accounts.permissions import DEFAULT_GROUPS, PERMISSIONS
+
+
+def test_seed_permissions_creates_permissions_and_groups(db):
+    call_command("seed_permissions")
+
+    assert Permission.objects.filter(
+        codename__in=[permission.codename for permission in PERMISSIONS]
+    ).count() == len(PERMISSIONS)
+
+    for group_name, codenames in DEFAULT_GROUPS.items():
+        group = Group.objects.get(name=group_name)
+        actual = set(group.permissions.values_list("codename", flat=True))
+        assert actual == set(codenames)

backend/apps/audit/__init__.py

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+

backend/apps/audit/api.py

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+from datetime import datetime
+from typing import Any
+
+from ninja import Router, Schema
+
+from apps.audit.models import OperationAuditLog
+
+router = Router(tags=["audit"])
+
+
+class OperationAuditLogOut(Schema):
+    id: int
+    module: str
+    action: str
+    target_type: str
+    target_id: str
+    request_snapshot: dict[str, Any]
+    result: str
+    ip_address: str | None
+    user_agent: str
+    created_at: datetime
+
+
+@router.get("/operation-logs", response=list[OperationAuditLogOut])
+def list_operation_logs(request):
+    return OperationAuditLog.objects.all()[:100]

backend/apps/audit/apps.py

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+from django.apps import AppConfig
+
+
+class AuditConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.audit"

backend/apps/audit/migrations/0001_initial.py

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+# Generated by Django 5.2.15 on 2026-06-30 07:47
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='OperationAuditLog',
+            fields=[
+                (
+                    'id',
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name='ID',
+                    ),
+                ),
+                ('module', models.CharField(max_length=80)),
+                ('action', models.CharField(max_length=80)),
+                ('target_type', models.CharField(max_length=80)),
+                ('target_id', models.CharField(blank=True, max_length=120)),
+                ('request_snapshot', models.JSONField(blank=True, default=dict)),
+                ('result', models.CharField(max_length=20)),
+                ('ip_address', models.GenericIPAddressField(blank=True, null=True)),
+                ('user_agent', models.TextField(blank=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                (
+                    'user',
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name='operation_audit_logs',
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+            options={
+                'ordering': ['-created_at'],
+                'indexes': [
+                    models.Index(fields=['module', 'action'], name='audit_opera_module_8f87af_idx'),
+                    models.Index(
+                        fields=['target_type', 'target_id'],
+                        name='audit_opera_target__560d76_idx',
+                    ),
+                    models.Index(fields=['created_at'], name='audit_opera_created_077b40_idx'),
+                ],
+            },
+        ),
+    ]

backend/apps/audit/models.py

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+from django.conf import settings
+from django.db import models
+
+
+class OperationAuditLog(models.Model):
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="operation_audit_logs",
+    )
+    module = models.CharField(max_length=80)
+    action = models.CharField(max_length=80)
+    target_type = models.CharField(max_length=80)
+    target_id = models.CharField(max_length=120, blank=True)
+    request_snapshot = models.JSONField(default=dict, blank=True)
+    result = models.CharField(max_length=20)
+    ip_address = models.GenericIPAddressField(null=True, blank=True)
+    user_agent = models.TextField(blank=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        ordering = ["-created_at"]
+        indexes = [
+            models.Index(fields=["module", "action"]),
+            models.Index(fields=["target_type", "target_id"]),
+            models.Index(fields=["created_at"]),
+        ]
+
+    def __str__(self) -> str:
+        return f"{self.module}.{self.action}:{self.result}"

backend/apps/audit/tests/__init__.py

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+

backend/apps/audit/tests/test_audit_api.py

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+from apps.audit.models import OperationAuditLog
+
+
+def test_list_operation_logs_returns_recent_logs(client, db):
+    OperationAuditLog.objects.create(
+        module="system",
+        action="health_check",
+        target_type="system",
+        target_id="health",
+        result="success",
+        request_snapshot={"path": "/api/system/health"},
+    )
+
+    response = client.get("/api/audit/operation-logs")
+
+    assert response.status_code == 200
+    payload = response.json()
+    assert len(payload) == 1
+    assert payload[0]["module"] == "system"
+    assert payload[0]["action"] == "health_check"

backend/apps/system/__init__.py

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+

backend/apps/system/api.py

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+from ninja import Router
+
+router = Router(tags=["system"])
+
+
+@router.get("/health")
+def health(request):
+    return {"status": "ok"}

backend/apps/system/apps.py

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+from django.apps import AppConfig
+
+
+class SystemConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.system"

backend/apps/system/tests/__init__.py

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+

backend/apps/system/tests/test_health_api.py

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+def test_health_endpoint_returns_ok(client):
+    response = client.get("/api/system/health")
+
+    assert response.status_code == 200
+    assert response.json() == {"status": "ok"}

backend/config/__init__.py

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+

backend/config/asgi.py

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+import os
+
+from django.core.asgi import get_asgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")
+
+application = get_asgi_application()

backend/config/celery.py

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+import os
+
+from celery import Celery
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")
+
+app = Celery("ai_ticket_platform")
+app.config_from_object("django.conf:settings", namespace="CELERY")
+app.autodiscover_tasks()

backend/config/settings/__init__.py

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+

backend/config/settings/base.py

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+import os
+from pathlib import Path
+
+BASE_DIR = Path(__file__).resolve().parents[3]
+
+SECRET_KEY = os.getenv("DJANGO_SECRET_KEY", "dev-only-change-me")
+DEBUG = os.getenv("DJANGO_DEBUG", "false").lower() == "true"
+ALLOWED_HOSTS = os.getenv("DJANGO_ALLOWED_HOSTS", "localhost,127.0.0.1").split(",")
+
+INSTALLED_APPS = [
+    "django.contrib.admin",
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "corsheaders",
+    "apps.accounts",
+    "apps.audit",
+    "apps.system",
+]
+
+MIDDLEWARE = [
+    "corsheaders.middleware.CorsMiddleware",
+    "django.middleware.security.SecurityMiddleware",
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.common.CommonMiddleware",
+    "django.middleware.csrf.CsrfViewMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+    "django.contrib.messages.middleware.MessageMiddleware",
+    "django.middleware.clickjacking.XFrameOptionsMiddleware",
+]
+
+ROOT_URLCONF = "config.urls"
+
+TEMPLATES = [
+    {
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "DIRS": [],
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "context_processors": [
+                "django.template.context_processors.debug",
+                "django.template.context_processors.request",
+                "django.contrib.auth.context_processors.auth",
+                "django.contrib.messages.context_processors.messages",
+            ],
+        },
+    }
+]
+
+WSGI_APPLICATION = "config.wsgi.application"
+ASGI_APPLICATION = "config.asgi.application"
+
+DATABASES = {
+    "default": {
+        "ENGINE": "django.db.backends.postgresql",
+        "NAME": os.getenv("POSTGRES_DB", "ai_ticket_platform"),
+        "USER": os.getenv("POSTGRES_USER", "ai_ticket"),
+        "PASSWORD": os.getenv("POSTGRES_PASSWORD", "ai_ticket"),
+        "HOST": os.getenv("POSTGRES_HOST", "localhost"),
+        "PORT": int(os.getenv("POSTGRES_PORT", "5432")),
+    }
+}
+
+LANGUAGE_CODE = "zh-hans"
+TIME_ZONE = "Asia/Shanghai"
+USE_I18N = True
+USE_TZ = True
+
+STATIC_URL = "static/"
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+
+CORS_ALLOWED_ORIGINS = os.getenv(
+    "CORS_ALLOWED_ORIGINS",
+    "http://localhost:5173",
+).split(",")
+
+CELERY_BROKER_URL = os.getenv("CELERY_BROKER_URL", "redis://localhost:6379/0")
+CELERY_RESULT_BACKEND = os.getenv("CELERY_RESULT_BACKEND", "redis://localhost:6379/1")

backend/config/settings/local.py

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+from .base import *  # noqa: F403
+
+DEBUG = True

backend/config/settings/test.py

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+from .base import *  # noqa: F403
+
+DATABASES = {
+    "default": {
+        "ENGINE": "django.db.backends.sqlite3",
+        "NAME": ":memory:",
+    }
+}
+
+PASSWORD_HASHERS = [
+    "django.contrib.auth.hashers.MD5PasswordHasher",
+]

backend/config/urls.py

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+from django.contrib import admin
+from django.urls import path
+from ninja import NinjaAPI
+
+from apps.audit.api import router as audit_router
+from apps.system.api import router as system_router
+
+api = NinjaAPI(title="AI Ticket Platform API", version="0.1.0")
+api.add_router("/system", system_router)
+api.add_router("/audit", audit_router)
+
+urlpatterns = [
+    path("admin/", admin.site.urls),
+    path("api/", api.urls),
+]

backend/config/wsgi.py

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+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")
+
+application = get_wsgi_application()

backend/manage.py

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+#!/usr/bin/env python
+import os
+import sys
+
+
+def main() -> None:
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")
+    from django.core.management import execute_from_command_line
+
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == "__main__":
+    main()

backend/pyproject.toml

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+[project]
+name = "ai-ticket-platform-backend"
+version = "0.1.0"
+description = "Backend for AI-native technical support ticket platform"
+requires-python = ">=3.12"
+dependencies = [
+  "Django>=5.0,<5.3",
+  "django-ninja>=1.3,<2.0",
+  "psycopg[binary]>=3.2,<4.0",
+  "celery>=5.4,<6.0",
+  "redis>=5.0,<6.0",
+  "django-cors-headers>=4.4,<5.0",
+  "pydantic>=2.8,<3.0",
+  "python-dotenv>=1.0,<2.0",
+]
+
+[build-system]
+requires = ["setuptools>=69"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+include = ["apps*", "config*"]
+
+[project.optional-dependencies]
+dev = [
+  "pytest>=8.2,<9.0",
+  "pytest-django>=4.8,<5.0",
+  "ruff>=0.6,<1.0",
+  "mypy>=1.11,<2.0",
+  "django-stubs[compatible-mypy]>=5.0,<6.0",
+]
+
+[tool.pytest.ini_options]
+DJANGO_SETTINGS_MODULE = "config.settings.test"
+python_files = ["test_*.py", "*_test.py"]
+testpaths = ["apps", "tests"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py312"
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "UP", "B"]
+
+[tool.mypy]
+python_version = "3.12"
+plugins = ["mypy_django_plugin.main"]
+ignore_missing_imports = true
+strict_optional = true
+
+[tool.django-stubs]
+django_settings_module = "config.settings.test"

backend/tests/__init__.py

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+

backend/tests/conftest.py

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+