fix: Remove nonexistent turso_mvcc parameter from v1.11.x docs

The turso_mvcc parameter does not exist in the Spice codebase. MVCC is
unconditionally enabled — PRAGMA journal_mode = 'mvcc' is set during
every TursoConnectionPool::new_with_timestamp_format call. The vNext
docs already correctly state that MVCC is automatically enabled.

Changes:
- Remove turso_mvcc from the configuration parameters list
- Remove turso_mvcc: enabled from YAML examples
- Update MVCC section to state MVCC is automatically enabled (matching
  vNext wording)

Author: claudespice

website/versioned_docs/version-1.11.x/components/data-accelerators/turso.md

@@ -60,7 +60,6 @@ datasets:
 Turso acceleration supports the following optional parameters under `acceleration.params`:
 
 - `turso_file` (string, default: `.spice/data/{dataset_name}.turso`): Path to the Turso database file. Only applies if `mode` is `file`. If the file does not exist, Spice creates it automatically.
-- `turso_mvcc` (string, default: `disabled`): Enable Multi-Version Concurrency Control (MVCC) for improved concurrent read/write performance. Values: `enabled`, `disabled`.
 - `internal_timestamp_format` (string, default: `rfc3339`): Internal timestamp storage format. See [Timestamp Storage](#timestamp-storage) section. Values: `rfc3339`, `integer_millis`.
 
 ### Example Configuration
@@ -77,7 +76,6 @@ datasets:
       refresh_check_interval: 10m
       params:
         turso_file: ./orders.turso
-        turso_mvcc: enabled
 ```
 
 Refer to the [datasets configuration reference](../../reference/spicepod/datasets#acceleration) for additional supported fields.
@@ -116,16 +114,9 @@ acceleration:
 
 ### MVCC Support
 
-Multi-Version Concurrency Control (MVCC) can be enabled for improved concurrent read/write performance:
+Multi-Version Concurrency Control (MVCC) is automatically enabled for all Turso-accelerated datasets. The Turso accelerator sets `PRAGMA journal_mode = 'mvcc'` during connection pool initialization, enabling concurrent transactions via `BEGIN CONCURRENT`.
 
-```yaml
-acceleration:
-  engine: turso
-  params:
-    turso_mvcc: enabled
-```
-
-When MVCC is enabled:
+When MVCC is active:
 
 - Concurrent reads and writes perform better
 - Indexes are not yet supported (a warning is logged if indexes are configured)