chore: update dependencies and adapt to updated crate APIs

Bumps core dependencies including ndarray, rand, hashbrown, niffler, ureq, sysinfo, indicatif, lru, and remove_dir_all. Adapts source code to accommodate breaking changes by migrating RNG initialization, adjusting HTTP response handling, and replacing the fs4 crate with standard library file locking. Adds a planning document for query benchmarking and sparse index regression tests.

src/obiskio/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2024"
 [dependencies]
 niffler = "3.0.0"
 rustix = { version = "1.1.4", features = ["process"] }
-lru = "0.12"
+lru = "0.18"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"