Bug: Flaky Rust tests - RocksDB lock and collection ordering

[malibio]

Description

Two Rust tests are failing intermittently/consistently:

1. test_node_service_idempotent_seeding - RocksDB Lock Issue

Retry 1/5: RocksDB lock not released, waiting 100ms: Failed to initialize SurrealDB with RocksDB backend
...
Error: "Failed to open store after 5 retries: Failed to initialize SurrealDB with RocksDB backend"

Root cause: Test isolation issue - RocksDB lock not being released between tests.

2. test_add_to_collection_assigns_order - Order Values Wrong

One order should be ~3.0, got [1.000582, 2.000869002, 2.001162001]

Root cause: May be related to recent SurrealDB optimization changes (PR #861).

Reproduction

cargo test test_node_service_idempotent_seeding --package nodespace-core --lib
cargo test test_add_to_collection_assigns_order --package nodespace-core --lib

Acceptance Criteria

• Both tests pass consistently
• RocksDB lock properly released between tests
• Collection ordering logic verified

[malibio]

Test baseline: Frontend: 3501 passed (104 files), Rust app: 25 passed, Rust core: 752 passed + 1 failed (test_node_service_idempotent_seeding - RocksDB lock), collection ordering test also failing (test_add_to_collection_assigns_order)