Bump SurrealDB to 3.1.3

Retarget the dependency bump from 3.1.2 to the latest 3.1.x (3.1.3).

- surrealdb crate and package version -> 3.1.3
- Cargo.lock refreshed via cargo update --precise (ferntree dropped,
  diskann 0.53, surrealmx 0.22)
- CHANGELOG [Unreleased] entry updated

Toolchain stays at 1.95 (still valid for 3.1.x); cargo check passes.

Author: emmanuel-keller

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog
 
 ## [Unreleased]
-- Upgrade to SurrealDB SDK 3.1.2 and bump the Rust toolchain to 1.95 [#165](https://github.com/surrealdb/surrealdb.java/pull/165).
+- Upgrade to SurrealDB SDK 3.1.3 and bump the Rust toolchain to 1.95 [#165](https://github.com/surrealdb/surrealdb.java/pull/165).
 
 ## [2.0.3] - 2026-05-29
 - Support Java `record` classes in `create` and `select` (JDK 16+ at runtime). Records are hydrated via their canonical constructor; POJO behaviour on JDK 8+ is unchanged [#156](https://github.com/surrealdb/surrealdb.java/pull/156).

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "surrealdb-java"
-version = "3.1.2"
+version = "3.1.3"
 authors = ["Emmanuel Keller <emmanuel.keller@surrealdb.com>"]
 edition = "2021"
 
@@ -19,7 +19,7 @@ opt-level = 3
 # Driver-specific dependencies (jni, once_cell, cargo-lock) are independent.
 [dependencies]
 jni = "0.21.1"
-surrealdb = { version = "3.1.2", default-features = false, features = ["rustls", "protocol-http", "protocol-ws"] }
+surrealdb = { version = "3.1.3", default-features = false, features = ["rustls", "protocol-http", "protocol-ws"] }
 serde = "1.0.228"
 serde_json = "1.0.149"
 rust_decimal = "1.40.0"