Initial commit: Backend API Phase 1a complete

- FastAPI backend with JWT auth
- PostgreSQL database schema
- Trees and Sessions CRUD APIs
- Export functionality (Markdown, Text, HTML)
- Docker setup for local development
- Alembic migrations

backend/app/models/__init__.py

@@ -0,0 +1,7 @@
+from .user import User
+from .team import Team
+from .tree import Tree
+from .session import Session
+from .attachment import Attachment
+
+__all__ = ["User", "Team", "Tree", "Session", "Attachment"]

backend/app/models/attachment.py

@@ -0,0 +1,34 @@
+import uuid
+from datetime import datetime
+from typing import Optional
+from sqlalchemy import String, Integer, DateTime, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class Attachment(Base):
+    __tablename__ = "attachments"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4
+    )
+    session_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("sessions.id"),
+        nullable=False
+    )
+    node_id: Mapped[Optional[str]] = mapped_column(String(100), nullable=True)
+    file_name: Mapped[str] = mapped_column(String(255), nullable=False)
+    file_type: Mapped[Optional[str]] = mapped_column(String(50), nullable=True)
+    file_size: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
+    storage_path: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
+    uploaded_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow
+    )
+
+    # Relationships
+    session: Mapped["Session"] = relationship("Session", back_populates="attachments")

backend/app/models/session.py

@@ -0,0 +1,46 @@
+import uuid
+from datetime import datetime
+from typing import Optional, Any
+from sqlalchemy import String, DateTime, ForeignKey, Boolean
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from app.core.database import Base
+
+
+class Session(Base):
+    __tablename__ = "sessions"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4
+    )
+    tree_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("trees.id"),
+        nullable=False,
+        index=True
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id"),
+        nullable=False,
+        index=True
+    )
+    tree_snapshot: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False)
+    path_taken: Mapped[list[str]] = mapped_column(JSONB, nullable=False, default=list)
+    decisions: Mapped[list[dict[str, Any]]] = mapped_column(JSONB, nullable=False, default=list)
+    started_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow,
+        index=True
+    )
+    completed_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True, index=True)
+    ticket_number: Mapped[Optional[str]] = mapped_column(String(100), nullable=True)
+    client_name: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
+    exported: Mapped[bool] = mapped_column(Boolean, default=False)
+
+    # Relationships
+    tree: Mapped["Tree"] = relationship("Tree", back_populates="sessions")
+    user: Mapped["User"] = relationship("User", back_populates="sessions")
+    attachments: Mapped[list["Attachment"]] = relationship("Attachment", back_populates="session")

backend/app/models/team.py

@@ -0,0 +1,25 @@
+import uuid
+from datetime import datetime
+from sqlalchemy import String, DateTime
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class Team(Base):
+    __tablename__ = "teams"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow
+    )
+
+    # Relationships
+    users: Mapped[list["User"]] = relationship("User", back_populates="team")
+    trees: Mapped[list["Tree"]] = relationship("Tree", back_populates="team")

backend/app/models/tree.py

@@ -0,0 +1,51 @@
+import uuid
+from datetime import datetime
+from typing import Optional, Any
+from sqlalchemy import String, Text, DateTime, ForeignKey, Boolean, Integer, Index
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from app.core.database import Base
+
+
+class Tree(Base):
+    __tablename__ = "trees"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    category: Mapped[Optional[str]] = mapped_column(String(100), nullable=True, index=True)
+    tree_structure: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False)
+    author_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id"),
+        nullable=True
+    )
+    team_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("teams.id"),
+        nullable=True,
+        index=True
+    )
+    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
+    version: Mapped[int] = mapped_column(Integer, default=1)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow,
+        onupdate=datetime.utcnow
+    )
+    usage_count: Mapped[int] = mapped_column(Integer, default=0)
+
+    # Relationships
+    author: Mapped[Optional["User"]] = relationship("User", back_populates="trees")
+    team: Mapped[Optional["Team"]] = relationship("Team", back_populates="trees")
+    sessions: Mapped[list["Session"]] = relationship("Session", back_populates="tree")
+
+    # Full-text search index will be created in migration

backend/app/models/user.py

@@ -0,0 +1,36 @@
+import uuid
+from datetime import datetime
+from typing import Optional
+from sqlalchemy import String, DateTime, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4
+    )
+    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
+    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    role: Mapped[str] = mapped_column(String(50), nullable=False, default="engineer")  # admin, engineer, viewer
+    team_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("teams.id"),
+        nullable=True
+    )
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime,
+        default=datetime.utcnow
+    )
+    last_login: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
+
+    # Relationships
+    team: Mapped[Optional["Team"]] = relationship("Team", back_populates="users")
+    trees: Mapped[list["Tree"]] = relationship("Tree", back_populates="author")
+    sessions: Mapped[list["Session"]] = relationship("Session", back_populates="user")