feat: Add Azure Cosmos DB store implementation

Add CosmosDBStore for Azure Cosmos DB NoSQL API support:
- Implements AsyncKeyValue protocol with full CRUD operations
- Uses partition key for collection isolation
- Supports TTL via Cosmos DB's native TTL feature
- Includes collection sanitization strategy
- Supports both client injection and URL/credential configuration
- Adds optional dependency: azure-cosmos>=4.7.0

Closes #292

Co-authored-by: Bill Easton <strawgate@users.noreply.github.com>

Author: github-actions[bot]

pyproject.toml

@@ -51,6 +51,7 @@ rocksdb = [
 duckdb = ["duckdb>=1.1.1", "pytz>=2025.2"]
 postgresql = ["asyncpg>=0.30.0"]
 firestore = ["google-cloud-firestore>=2.13.0", "google-auth>=2.24.0"]
+cosmosdb = ["azure-cosmos>=4.7.0"]
 wrappers-encryption = ["cryptography>=45.0.0"]
 docs = [
     "mkdocs>=1.6.0",
@@ -61,7 +62,7 @@ docs = [
 
 [dependency-groups]
 dev = [
-    "py-key-value-aio[memory,disk,filetree,redis,elasticsearch,opensearch,memcached,mongodb,vault,dynamodb,s3,rocksdb,duckdb,firestore,postgresql]",
+    "py-key-value-aio[memory,disk,filetree,redis,elasticsearch,opensearch,memcached,mongodb,vault,dynamodb,s3,rocksdb,duckdb,firestore,postgresql,cosmosdb]",
     "py-key-value-aio[valkey]; platform_system != 'Windows'",
     "py-key-value-aio[aerospike]; platform_system != 'Windows'",
     "py-key-value-aio[keyring]",

src/key_value/aio/stores/cosmosdb/__init__.py

@@ -0,0 +1,3 @@
+from key_value.aio.stores.cosmosdb.store import CosmosDBStore
+
+__all__ = ["CosmosDBStore"]