End-of-phase cleanup of items flagged across review passes for tasks
1.1, 1.2, and 1.3:
1. crates/core/src/lib.rs: pub mod power moved to alphabetical
position (between paths and process_watch).
2. crates/core/src/power.rs: use statements moved to top of file
(above the PowerState enum) per Rust convention.
3. crates/core/src/power.rs: parse_power_state_from_dir docstring
tightened to acknowledge that read_dir.flatten() silently skips
per-entry errors. Theoretical hazard only on world-readable
sysfs, but the previous wording overstated the guarantee.
No behavioural change. All 40 magnotia-core tests still green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
4f3c063008