docs: adopt Embedded/Distributed terminology across docs and SDKs (#4713)

## Summary

Adopts the product terminology guide across the docs site pages, SDK
docstrings and error messages. "LanceDB OSS" and local mode become
**LanceDB Embedded**. "Remote" as the execution model becomes **LanceDB
Distributed**, which LanceDB Enterprise provides. Where free vs paid is
the point, pages contrast "LanceDB Embedded (open source)" with "LanceDB
Enterprise". This is a first trial of the Embedded name, so reviewers
can judge it in context.

- **Embedded vs Distributed** for where execution runs (`optimize()`,
consistency, branching, maintenance). Main pages define it once:
"LanceDB Enterprise runs LanceDB Distributed: …"
- **LanceDB Cloud** is kept only for legacy-Cloud specifics (`db://`
region, the brute-force KNN limit) and marked legacy. "Cloud and
Enterprise" becomes Enterprise or Distributed.
- **Plan executor** becomes "executor" or the fleet name.
- **Error messages** change, e.g. `optimize is not supported for remote
tables.` → `... in LanceDB Distributed.` Tests that match on them are
updated.
- **Vale rules** (`EmbeddedName`, `OSSProduct`, `RemoteExecution`,
`DistributedEnterprise`, `LegacyCloud`, `InternalNames`) enforce the
terms in prose.

Unchanged: identifiers (`availability.oss`, the `remote` module and
feature, `RemoteTable`, `db://`), heading anchors, internal code
comments, and Geneva.

## Evidence

- Rust lib tests for the changed messages and the Python tests in
`test_remote_db.py`, `test_materialized_views.py` and `test_table.py`
pass locally.
- Not run locally:
- The Node tests: `remote.test.ts` and `table.test.ts` have updated
assertions.
  - Vale.
  - The `experimental_functions`-marked materialized-view tests.
- `docs/src` API reference was hand-edited to match the docstrings
rather than regenerated.

## Merge Risk

**Door:** two-way; prose and message text only.
**Blast Radius:** `docs`, `error-messages`: callers matching on old
error strings would break.

Companion PRs: lancedb/docs (assembler labels, STYLE.md) and sophon
(Enterprise pages).

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

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

java/README.md

@@ -2,9 +2,9 @@
 
 ## Configuration and Initialization
 
-### LanceDB Cloud
+### LanceDB Cloud (legacy)
 
-For LanceDB Cloud, use the simplified builder API:
+For LanceDB Cloud, the legacy hosted service, use the simplified builder API:
 
 ```java
 import com.lancedb.LanceDbNamespaceClientBuilder;
@@ -19,7 +19,7 @@ LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
 
 ### LanceDB Enterprise
 
-For Enterprise deployments, use your custom endpoint:
+For LanceDB Enterprise deployments, use your custom endpoint:
 
 ```java
 LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()

java/lancedb-core/src/main/java/com/lancedb/LanceDbNamespaceClientBuilder.java

@@ -22,7 +22,7 @@ import java.util.Optional;
 /**
  * Util class to help construct a {@link LanceNamespace} for LanceDB.
  *
- * <p>For LanceDB Cloud, use the simplified builder API:
+ * <p>For LanceDB Cloud (legacy hosted service), use the simplified builder API:
  *
  * <pre>{@code
  * import org.lance.namespace.LanceNamespace;

java/lancedb-core/src/main/java/com/lancedb/LanceDbRestClient.java

@@ -27,7 +27,7 @@ import java.io.IOException;
 import java.io.UncheckedIOException;
 
 /**
- * Minimal HTTP client for LanceDB Cloud and Enterprise routes that the Lance Namespace
+ * Minimal HTTP client for LanceDB Enterprise routes that the Lance Namespace
  * specification does not cover.
  *
  * <p>Most table operations reach LanceDB through {@link org.lance.namespace.LanceNamespace}, which

java/lancedb-core/src/main/java/com/lancedb/LanceDbTableRTE.java

@@ -22,7 +22,7 @@ import java.util.Optional;
 import java.util.OptionalLong;
 
 /**
- * The RTE write path for one LanceDB Cloud or Enterprise table.
+ * The RTE write path for one LanceDB Enterprise table.
  *
  * <p>Installing an {@link RTEWriteSpec} routes {@code mergeInsert} upserts through Lance's RTE — an
  * LSM-style append — instead of the standard merge path. Rows land in an in-memory memtable, freeze