rand 0.8 depends on getrandom 0.2, which refuses to compile on
wasm32-unknown-unknown without its "js" feature (it needs to call into the
Web Crypto API via wasm-bindgen). Bevy's own rand usage sits on getrandom
0.3+, which enables this by default, so the web build only broke once we
added a direct rand 0.8 dep in 76be513.
Force-enabling getrandom/js in the wasm32 target deps section unblocks
`trunk build`. Desktop is unaffected (the cfg gates it to wasm only).
Caught by the Task 8 wasm cargo-check gate.
ChaCha8Rng needs both crates: rand (the core traits Rng/SeedableRng) and
rand_chacha (the ChaCha8Rng type, split out of rand since 0.9). rand was
already a transitive dep via bevy_math but not declared directly.
Pinned to 0.8/0.3 (LTS, API-stable with the Bevy 0.19 ecosystem) rather
than the newer 0.10 line, which would force a wider dep upgrade.
