Phayriosis Reborn maintenance note - Phase 1 command cleanup

The legacy in-game configuration screen is being retired in favor of a world-creation settings system.
The two useful administrative tuning commands are intentionally retained as fallback/testing tools, but their names no longer use the obsolete "config" label.

Renamed:
- phayriosis_config_set_block-spread-speed -> phayriosis_set_block-spread-speed
- phayriosis_config_set_max-infectable-hardness -> phayriosis_set_max-infectable-hardness

Behavior and backing variables are unchanged. Only the Brigadier command literals were changed.
Do not remove the backing world/map variables during Phase 2; the future world-creation UI should write to the replacement per-world settings backend and these commands can later target that same backend.

Verifier note:
Do not NOP generated methods in-place without regenerating StackMapTable frames. Previous Phase 1 attempt demonstrated this causes VerifyError on Java 17. Prefer source-level rebuilds, whole-method replacements with valid frames, or constant-pool-only changes when appropriate.
