fix: propagate managed versioning for namespace connection (#3111)

Without this fix, if user directly use the native table to do operations
like `add_columns`, even if it is configured to use namespace db
connection, it is not really propagated through.

The fix is to bring lancedb's python binding up to date and do a similar
implementation as https://github.com/lance-format/lance/pull/5968, and
make sure the namespace is fully propagated through all the related
calls.

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

python/src/lib.rs

@@ -23,6 +23,7 @@ pub mod connection;
 pub mod error;
 pub mod header;
 pub mod index;
+pub mod namespace;
 pub mod permutation;
 pub mod query;
 pub mod session;