chore: project cleanup and prepare for dual-track processing refactor

- Removed all test files and directories
- Deleted outdated documentation (will be rewritten)
- Cleaned up temporary files, logs, and uploads
- Archived 5 completed OpenSpec proposals
- Created new dual-track-document-processing proposal with complete OpenSpec structure
  - Dual-track architecture: OCR track (PaddleOCR) + Direct track (PyMuPDF)
  - UnifiedDocument model for consistent output
  - Support for structure-preserving translation
- Updated .gitignore to prevent future test/temp files

This is a major cleanup preparing for the complete refactoring of the document processing pipeline.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/tests/conftest.py

@@ -1,138 +0,0 @@
-"""
-V2 API Test Configuration and Fixtures
-Provides test fixtures for authentication, database, and API testing
-"""
-
-import pytest
-from fastapi.testclient import TestClient
-from sqlalchemy import create_engine
-from sqlalchemy.orm import sessionmaker
-from sqlalchemy.pool import StaticPool
-
-# IMPORTANT: Monkey patch database module BEFORE importing app
-# This prevents the app from connecting to production database
-import app.core.database as db_module
-
-# Create a test engine for the entire test session
-_test_engine = create_engine(
-    "sqlite:///:memory:",
-    connect_args={"check_same_thread": False},
-    poolclass=StaticPool,
-)
-
-# Replace the global engine and SessionLocal
-db_module.engine = _test_engine
-db_module.SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=_test_engine)
-
-# Now safely import app (it will use our test database)
-from app.main import app
-from app.core.database import Base, get_db
-from app.core.security import create_access_token
-from app.models.user import User
-from app.models.task import Task
-
-
-@pytest.fixture(scope="function")
-def engine():
-    """Get test database engine and reset tables for each test"""
-    Base.metadata.drop_all(bind=_test_engine)
-    Base.metadata.create_all(bind=_test_engine)
-    yield _test_engine
-    # Tables will be dropped at the start of next test
-
-
-@pytest.fixture(scope="function")
-def db(engine):
-    """Create test database session"""
-    TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
-    db = TestingSessionLocal()
-    try:
-        yield db
-    finally:
-        db.close()
-
-
-@pytest.fixture(scope="function")
-def client(db):
-    """Create FastAPI test client with test database"""
-    # Override get_db to use the same session as the test
-    def override_get_db():
-        try:
-            yield db
-        finally:
-            # Don't close the session, it's managed by the db fixture
-            pass
-
-    app.dependency_overrides[get_db] = override_get_db
-    with TestClient(app) as test_client:
-        yield test_client
-    app.dependency_overrides.clear()
-
-
-@pytest.fixture
-def test_user(db):
-    """Create a test user"""
-    # Ensure test_user is always created first by checking if it exists
-    user = db.query(User).filter(User.email == "test@example.com").first()
-    if not user:
-        user = User(
-            email="test@example.com",
-            display_name="Test User",
-            is_active=True
-        )
-        db.add(user)
-        db.commit()
-        db.refresh(user)
-    return user
-
-
-@pytest.fixture
-def admin_user(db):
-    """Create an admin user"""
-    user = db.query(User).filter(User.email == "ymirliu@panjit.com.tw").first()
-    if not user:
-        user = User(
-            email="ymirliu@panjit.com.tw",
-            display_name="Admin User",
-            is_active=True
-        )
-        db.add(user)
-        db.commit()
-        db.refresh(user)
-    return user
-
-
-@pytest.fixture
-def auth_token(test_user):
-    """Create authentication token for test user"""
-    token_data = {
-        "sub": str(test_user.id),
-        "email": test_user.email
-    }
-    return create_access_token(token_data)
-
-
-@pytest.fixture
-def admin_token(admin_user):
-    """Create authentication token for admin user"""
-    token_data = {
-        "sub": str(admin_user.id),
-        "email": admin_user.email
-    }
-    return create_access_token(token_data)
-
-
-@pytest.fixture
-def test_task(test_user, db):
-    """Create a test task (depends on test_user to ensure user exists first)"""
-    task = Task(
-        user_id=test_user.id,
-        task_id="test-task-123",
-        filename="test.pdf",
-        file_type="application/pdf",
-        status="pending"
-    )
-    db.add(task)
-    db.commit()
-    db.refresh(task)
-    return task