Fix compatibility with recent crates

[texodus]

This PR fixes cargo dependency conflicts caused by multiple versions of the same crate coexisting in the workspace, and updates some pinned dependencies to their latest compatible versions.

• Eliminate duplicate crate versions in Cargo.lock by unifying base64, serde-wasm-bindgen, fallible-iterator, pyo3-build-config, and target-lexicon to single versions across the workspace.
• Remove rand-unique dependency from perspective-client, avoiding version conflicts with rand/getrandom.
• Loosen version pins for rand, getrandom, axum, and wasm-bindgen-cli-support.
• Bump dependency versions for wasm-bindgen 0.2.106 -> 0.2.108, js-sys/web-sys 0.3.83 -> 0.3.85, base64 0.13 -> 0.22, itertools 0.10 -> 0.14, thiserror 1.x -> 2.x (in perspective-js), procss 0.1.17 -> 0.1.18, pyo3-build-config 0.22 -> 0.25.
• Fix rust-axum example to work around Cargo feature unification issues with wasm_bindgen_futures Send bounds when building inside the perspective workspace.