feat: add decision API routes with tests

PUT /api/decisions/{listing_id} to set decision,
GET /api/decisions to list all user decisions,
DELETE /api/decisions/{listing_id} to remove a decision.
All 6 API route tests pass.

api/decision_routes.py

@@ -0,0 +1,111 @@
+"""API routes for listing decisions (like/dislike)."""
+import logging
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel, Field
+
+from api.auth import User, get_current_user
+from database import engine
+from repositories.decision_repository import DecisionRepository
+from repositories.user_repository import UserRepository
+from services import decision_service
+
+logger = logging.getLogger("uvicorn")
+
+decision_router = APIRouter(prefix="/api/decisions", tags=["decisions"])
+
+
+class SetDecisionRequest(BaseModel):
+    decision: str = Field(description="'liked' or 'disliked'")
+    listing_type: str = Field(default="RENT", description="'RENT' or 'BUY'")
+
+
+class DecisionResponse(BaseModel):
+    id: int
+    listing_id: int
+    listing_type: str
+    decision: str
+    created_at: str
+    updated_at: str
+
+
+def _get_user_id(user: User) -> int:
+    """Resolve auth User to database user ID."""
+    user_repo = UserRepository(engine)
+    db_user = user_repo.get_user_by_email(user.email)
+    if db_user is None:
+        db_user = user_repo.create_user(user.email)
+    if db_user.id is None:
+        raise HTTPException(status_code=500, detail="Failed to create user")
+    return db_user.id
+
+
+@decision_router.put("/{listing_id}", response_model=DecisionResponse)
+async def set_decision(
+    user: Annotated[User, Depends(get_current_user)],
+    listing_id: int,
+    body: SetDecisionRequest,
+) -> DecisionResponse:
+    """Set a decision (like/dislike) on a listing."""
+    user_id = _get_user_id(user)
+    repo = DecisionRepository(engine)
+    try:
+        result = decision_service.set_decision(
+            repo,
+            user_id=user_id,
+            listing_id=listing_id,
+            listing_type=body.listing_type,
+            decision=body.decision,
+        )
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    return DecisionResponse(
+        id=result.id,  # type: ignore[arg-type]
+        listing_id=result.listing_id,
+        listing_type=result.listing_type,
+        decision=result.decision,
+        created_at=result.created_at.isoformat(),
+        updated_at=result.updated_at.isoformat(),
+    )
+
+
+@decision_router.get("", response_model=list[DecisionResponse])
+async def get_decisions(
+    user: Annotated[User, Depends(get_current_user)],
+) -> list[DecisionResponse]:
+    """Get all decisions for the current user."""
+    user_id = _get_user_id(user)
+    repo = DecisionRepository(engine)
+    decisions = decision_service.get_decisions(repo, user_id=user_id)
+    return [
+        DecisionResponse(
+            id=d.id,  # type: ignore[arg-type]
+            listing_id=d.listing_id,
+            listing_type=d.listing_type,
+            decision=d.decision,
+            created_at=d.created_at.isoformat(),
+            updated_at=d.updated_at.isoformat(),
+        )
+        for d in decisions
+    ]
+
+
+@decision_router.delete("/{listing_id}")
+async def delete_decision(
+    user: Annotated[User, Depends(get_current_user)],
+    listing_id: int,
+    listing_type: str = "RENT",
+) -> dict[str, bool]:
+    """Remove a decision (back to neutral)."""
+    user_id = _get_user_id(user)
+    repo = DecisionRepository(engine)
+    deleted = decision_service.clear_decision(
+        repo,
+        user_id=user_id,
+        listing_id=listing_id,
+        listing_type=listing_type,
+    )
+    if not deleted:
+        raise HTTPException(status_code=404, detail="Decision not found")
+    return {"success": True}