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)

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

nodejs/src/lib.rs

@@ -14,6 +14,7 @@ pub mod merge;
 mod query;
 pub mod remote;
 mod rerankers;
+mod session;
 mod table;
 mod util;
 
@@ -34,6 +35,9 @@ pub struct ConnectionOptions {
     ///
     /// The available options are described at https://lancedb.github.io/lancedb/guides/storage/
     pub storage_options: Option<HashMap<String, String>>,
+    /// (For LanceDB OSS only): the session to use for this connection. Holds
+    /// shared caches and other session-specific state.
+    pub session: Option<session::Session>,
 
     /// (For LanceDB cloud only): configuration for the remote HTTP client.
     pub client_config: Option<remote::ClientConfig>,