feat: MTG database integration with Redis caching

- Added MTG card ORM models (mtg_cards, mtg_sets tables)
- Created card_database service with search, get_by_name, get_by_set
- Added Redis client with caching layer (3600s TTL default)
- Created card router with caching on all endpoints:
  - Search cards (5min cache)
  - Get card by name (10min cache)
  - Get cards by set (15min cache)
  - Get card types/rarities (30min cache)
  - Get sets (1hr cache)
  - Get statistics (1hr cache)
- Updated settings.py:
  - Added JWT_SECRET_KEY field
  - Added DB_CONFIG and REDIS_CONFIG dictionaries
- Updated security.py to use JWT_SECRET_KEY with fallback
- Updated auth.py to use timezone-aware datetimes
- Updated refresh_mtg.py to use settings instead of os.environ
- Updated mtg_monitor.py to use settings for connections
- Added services package with __init__.py

All 20 tests passing.

scripts/init-db.sql

@@ -0,0 +1,60 @@
+-- Initialize MTG data database
+CREATE DATABASE mtgdata;
+
+-- Create extensions
+CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
+CREATE EXTENSION IF NOT EXISTS "pg_trgm";
+
+-- Create mtgjson tables
+CREATE TABLE IF NOT EXISTS mtg_sets (
+    id SERIAL PRIMARY KEY,
+    code VARCHAR(10) UNIQUE NOT NULL,
+    name VARCHAR(255) NOT NULL,
+    type VARCHAR(50),
+    release_date DATE,
+    base_set_size INTEGER,
+    total_size INTEGER,
+    is_foil_only BOOLEAN DEFAULT FALSE,
+    is_non_foil_only BOOLEAN DEFAULT FALSE,
+    digital BOOLEAN DEFAULT FALSE,
+    icon_svg_url TEXT,
+    parent_code VARCHAR(10),
+    mtgo_code VARCHAR(10),
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS mtg_cards (
+    id SERIAL PRIMARY KEY,
+    set_id INTEGER REFERENCES mtg_sets(id),
+    name VARCHAR(255) NOT NULL,
+    mana_cost TEXT,
+    type_line VARCHAR(255),
+    oracle_text TEXT,
+    power VARCHAR(10),
+    toughness VARCHAR(10),
+    rarity VARCHAR(50),
+    layout VARCHAR(50),
+    artist VARCHAR(255),
+    flavor_text TEXT,
+    numbers VARCHAR(50),
+    identifiers JSONB,
+    images JSONB,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX idx_mtg_cards_set_id ON mtg_cards(set_id);
+CREATE INDEX idx_mtg_cards_name ON mtg_cards(name);
+CREATE INDEX idx_mtg_cards_type ON mtg_cards(type_line);
+
+CREATE TABLE IF NOT EXISTS mtg_refresh_log (
+    id SERIAL PRIMARY KEY,
+    refresh_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    status VARCHAR(50) NOT NULL,
+    cards_updated INTEGER DEFAULT 0,
+    sets_updated INTEGER DEFAULT 0,
+    error_message TEXT,
+    duration_seconds INTEGER
+);
+
+CREATE INDEX idx_mtg_refresh_log_date ON mtg_refresh_log(refresh_date);