feat(bevy_skills): add skill progression system for Bevy 0.18

[h0lybyte]

Summary

• New bevy_skills crate at packages/rust/bevy/bevy_skills/
• Tracks per-entity skill XP and levels via SkillProfile component
• SkillRegistry resource for skill definitions (mining, woodcutting, cooking, etc.)
• Quadratic XpCurve with configurable base, scaling, and max level (default 99)
• Message-driven flow using Bevy 0.18 MessageReader/MessageWriter API
• GrantXpMsg / LevelUpMsg for XP granting and level-up notifications
• SkillCheckMsg / SkillCheckResultMsg for gating interactions by skill level
• 3 unit tests for XP curve math

Test plan

• cargo check -p bevy_skills passes
• cargo test -p bevy_skills passes (3 tests)
• CI validation

[github-actions]

Dependency Review

The following issues were found:

• ✅ 0 vulnerable package(s)
• ✅ 0 package(s) with incompatible licenses
• ✅ 0 package(s) with invalid SPDX license definitions
• ⚠️ 3 package(s) with unknown licenses.

See the Details below.

License Issues

packages/rust/bevy/bevy_skills/Cargo.toml

Package	Version	License	Issue Type
bevy	>= 0.18.0, < 0.19.0	Null	Unknown License
serde	>= 1.0.0, < 2.0.0	Null	Unknown License
serde_json	>= 1.0.0, < 2.0.0	Null	Unknown License

OpenSSF Scorecard

Package	Version	Score	Details
cargo/bevy	>= 0.18.0, < 0.19.0	Unknown	Unknown
cargo/serde	>= 1.0.0, < 2.0.0	Unknown	Unknown
cargo/serde_json	>= 1.0.0, < 2.0.0	Unknown	Unknown

Scanned Files

• packages/rust/bevy/bevy_skills/Cargo.toml