fix(python): route async remote blob reads through server (#4306)

## Cause

Async remote pandas conversion could call `AsyncTable.to_lance()`, which
opened the server's table storage URI in the client process. This
bypassed server query and authorization APIs. The first repair routed
blob reads through the server, but a query and subsequent blob fetch
could resolve different table snapshots after replacement or compaction.

## Fix

- Reject `AsyncTable.to_lance()` for remote tables before requesting a
table URI.
- Convert remote nonblob and blob description results through the server
Arrow path.
- Reject automatic remote byte and lazy blob materialization until the
server can bind the query and fetches to one verified table identity and
version. The default lazy mode now raises `NotImplementedError` when a
blob column is projected; callers can request
`blob_mode="descriptions"`.

## Validation

- Mocked remote tests cover direct storage rejection, description
results, byte and lazy rejection before any blob fetch, and nonblob
projections.
- Focused local and remote blob tests passed (19 tests). `ruff check .`,
`ruff format .`, and pyright passed.

Fixes #4272

<!-- lance-gatekeeper-fix:v1 agent=35937e6e1d968f62eea59adcc56c84e9
generation=1 -->

---------

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>

python/src/table.rs

@@ -917,6 +917,11 @@ impl Table {
         self.inner.is_some()
     }
 
+    /// Whether this table has a local Lance dataset that the client may open.
+    pub fn _is_native(&self) -> PyResult<bool> {
+        Ok(self.inner_ref()?.as_native().is_some())
+    }
+
     /// Closes the table, releasing any resources associated with it.
     pub fn close(&mut self) {
         self.inner.take();