Phayriosis Reborn Continued 0.0.20.15 - common config bridge

Purpose:
- Generate config/phayriosisreborn-common.toml for modpacks and dedicated servers.
- Mirror Create World settings into a readable file-backed default profile.
- Expose command-equivalent startup phase/points/max-power controls without requiring a player command.

Precedence:
- New worlds use the file defaults unless the Create World Phayriosis screen was explicitly applied.
- The Create World screen itself initializes from the file defaults, so pack authors can ship a profile users can see/edit.
- Existing worlds are preserved unless override_existing_world_settings=true.
- Infection progress is never reset on existing worlds unless apply_starting_state_to_existing_worlds=true.

Implementation:
- No tick polling. File is loaded once and world application occurs from Forge ServerStartedEvent after the overworld is registered.
- Legacy MapVariables are mirrored whenever file settings are applied so old procedures continue reading the same values.
- starting_phase follows the existing phase command thresholds: 1=0, 2=200, 3=3000, 4=10000, 5=200000, 6=500000, 7=1000000, 8=2500000 points.
- start_at_max_power mirrors the existing max-power command counters/adaptation flags.

Continuation:
- If runtime reload is later requested, add an operator-only reload command rather than polling the file.
