perf(ecstore): guard inline data-read metadata early-stop (#6069)

Add a default-off inline-only data-read metadata early-stop gate that verifies inline plaintext before cancelling pending metadata tasks.

Keep non-inline, prepared, and request-shape-sensitive reads on full fanout, and record scheduled/completed/cancelled ReadVersion lifecycle metrics for normal fanout completion.

Co-authored-by: heihutu <heihutu@gmail.com>

crates/scanner/src/lib.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#![recursion_limit = "256"]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![warn(
     // missing_docs,