feat: allow Python and Typescript users to create Sessions (#2530)

## Summary
- Exposes `Session` in Python and Typescript so users can set the
`index_cache_size_bytes` and `metadata_cache_size_bytes`
* The `Session` is attached to the `Connection`, and thus shared across
all tables in that connection.
- Adds deprecation warnings for table-level cache configuration


🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Claude <noreply@anthropic.com>

python/python/tests/test_session.py

@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright The LanceDB Authors
+
+import lancedb
+
+
+def test_session_cache_configuration(tmp_path):
+    """Test Session cache configuration and basic functionality."""
+    # Create session with small cache limits for testing
+    index_cache_size = 1024 * 1024  # 1MB
+    metadata_cache_size = 512 * 1024  # 512KB
+
+    session = lancedb.Session(
+        index_cache_size_bytes=index_cache_size,
+        metadata_cache_size_bytes=metadata_cache_size,
+    )
+
+    # Record initial cache state
+    initial_cache_size = session.size_bytes
+    initial_cache_items = session.approx_num_items
+
+    # Test session works with database connection
+    db = lancedb.connect(tmp_path, session=session)
+
+    # Create and use a table to exercise the session
+    data = [{"id": i, "text": f"item {i}"} for i in range(100)]
+    table = db.create_table("test", data)
+    results = list(table.to_arrow().to_pylist())
+
+    assert len(results) == 100
+
+    # Verify cache usage increased after operations
+    final_cache_size = session.size_bytes
+    final_cache_items = session.approx_num_items
+
+    assert final_cache_size > initial_cache_size  # Cache should have grown
+    assert final_cache_items >= initial_cache_items  # Items should not decrease
+    assert initial_cache_size < index_cache_size + metadata_cache_size