Phase 3: Schema Layer - Pydantic v2 migration, deduplication, and missing schemas

- Migrated all schemas to Pydantic v2 syntax (model_config, ConfigDict)
- Fixed mutable default in ProtoMessageBase using Field(default_factory=datetime.now)
- Consolidated CardCollection and Wishlist schemas in user_card_collection.py
- Created game_schemas.py with GameCreate, GameResponse, GameJoinRequest, etc.
- Created mtg_card_schemas.py with MtgCardResponse, MtgCardSearchRequest, etc.
- Added CardImportBatchCreate, CardImportBatchResponse, UserCardImportCreate/Response schemas
- Fixed duplicate UserCardImportRecord class between card_import_batch.py and user_card_import_record.py
- Updated __init__.py with comprehensive schema exports
- Created verify_schemas.py for schema-model matching verification

backend/app/schemas/card_import_schemas.py

@@ -4,7 +4,7 @@ Pydantic schemas for card import feature.
 Provides request/response models for importing card collections
 and using them for deckbuilding.
 """
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, ConfigDict
 from typing import List, Optional, Dict, Any
 from datetime import datetime
 
@@ -53,6 +53,65 @@ class CardImportSummary(BaseModel):
     import_id: Optional[int] = None
 
 
+# ===== Card Import Batch Schemas =====
+
+class CardImportBatchCreate(BaseModel):
+    """Card import batch creation request."""
+    user_id: int
+    card_names: List[str] = Field(..., min_length=1, max_length=10000)
+    source: Optional[str] = None  # 'manual', 'mtgjson', 'deck_text'
+
+
+class CardImportBatchResponse(BaseModel):
+    """Card import batch response."""
+    id: int
+    user_id: int
+    card_names: List[str]
+    source: Optional[str]
+    status: str  # 'pending', 'processing', 'completed', 'failed'
+    total_cards: int
+    matched_cards: int
+    unmatched_cards: int
+    created_at: datetime
+    updated_at: datetime
+    
+    model_config = ConfigDict(from_attributes=True)
+
+
+class UserCardImportCreate(BaseModel):
+    """User card import request."""
+    batch_id: int
+    card_id: int
+    quantity: int = Field(1, ge=1)
+    match_confidence: Optional[float] = None
+
+
+class UserCardImportResponse(BaseModel):
+    """User card import response."""
+    id: int
+    user_id: int
+    batch_id: int
+    card_id: int
+    quantity: int
+    match_confidence: Optional[float]
+    created_at: datetime
+    
+    model_config = ConfigDict(from_attributes=True)
+
+
+class UserCardImportRecordResponse(BaseModel):
+    """User card import record response."""
+    id: int
+    user_id: int
+    card_id: int
+    batch_id: int
+    quantity: int
+    source: Optional[str]
+    created_at: datetime
+    
+    model_config = ConfigDict(from_attributes=True)
+
+
 # Generic response models
 class MessageResponse(BaseModel):
     """Generic message response."""