feat: add Pydantic schemas for branching, handoffs, and resolution outputs

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

backend/app/schemas/session_resolution.py

@@ -0,0 +1,42 @@
+"""Pydantic schemas for session resolution outputs."""
+from __future__ import annotations
+from typing import Any
+from uuid import UUID
+from datetime import datetime
+from pydantic import BaseModel, Field
+
+
+class ResolutionOutputResponse(BaseModel):
+    id: UUID
+    session_id: UUID
+    output_type: str
+    generated_content: str
+    structured_data: dict[str, Any] | None
+    edited_content: str | None
+    status: str
+    pushed_to: str | None
+    pushed_at: datetime | None
+    pushed_reference: str | None
+    generated_by_model: str
+    created_at: datetime
+    updated_at: datetime
+    model_config = {"from_attributes": True}
+
+
+class ResolutionOutputEditRequest(BaseModel):
+    edited_content: str = Field(..., min_length=1)
+
+
+class ResolutionOutputPushRequest(BaseModel):
+    destination: str = Field(..., pattern="^(psa|kb_library|clipboard|email)$")
+
+
+class ResolutionOutputPushResponse(BaseModel):
+    output_id: UUID
+    status: str
+    pushed_to: str
+    pushed_reference: str | None = None
+
+
+class AllResolutionOutputsResponse(BaseModel):
+    outputs: list[ResolutionOutputResponse]