feat: add ScriptBuilderSession model, migration, and schemas

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/models/script_builder_session.py

@@ -0,0 +1,76 @@
+"""Script Builder session model.
+
+Tracks AI-powered script generation conversations.
+"""
+import uuid
+from datetime import datetime, timezone
+from typing import Optional, Any, TYPE_CHECKING
+
+from sqlalchemy import String, Text, DateTime, ForeignKey, Integer
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+
+from app.core.database import Base
+
+if TYPE_CHECKING:
+    from app.models.user import User
+
+
+class ScriptBuilderSession(Base):
+    """A conversation session in the AI Script Builder."""
+    __tablename__ = "script_builder_sessions"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+        index=True,
+    )
+    team_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("teams.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    language: Mapped[str] = mapped_column(
+        String(30), nullable=False, default="powershell",
+        comment="Script language: powershell, bash, python",
+    )
+    title: Mapped[Optional[str]] = mapped_column(
+        String(200), nullable=True,
+        comment="Auto-generated from first AI response",
+    )
+    messages: Mapped[list[dict[str, Any]]] = mapped_column(
+        JSONB, nullable=False, default=list,
+        comment="Array of {role, content, script?, script_filename?, timestamp}",
+    )
+    latest_script: Mapped[Optional[str]] = mapped_column(
+        Text, nullable=True,
+        comment="Most recent generated script for quick access",
+    )
+    latest_script_filename: Mapped[Optional[str]] = mapped_column(
+        String(200), nullable=True,
+        comment="Filename of the latest generated script",
+    )
+    message_count: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=0,
+    )
+    ai_session_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("ai_sessions.id", ondelete="SET NULL"),
+        nullable=True,
+        comment="Link to FlowPilot session if launched from there",
+    )
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )
+
+    # Relationships
+    user: Mapped["User"] = relationship("User")