fix: reject out-of-range led brightness instead of silently clamping

led accepted any u16 and main.rs clamped to 0..=1000 with no feedback,
inconsistent with sidetone which rejects out-of-range at parse time.
Add a clap range validator (0..=1000) and drop the silent clamp, so
invalid input now fails loudly.

Further quality-audit follow-ups:
- remove dead BragiDevice::open() (no caller; binary uses open_with_verbose)
- add tests: led range validation, format_battery for all status
  variants, waybar "unknown" class

Bump 0.1.2 -> 0.1.3.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "corsairctl"
-version = "0.1.2"
+version = "0.1.3"
 edition = "2024"
 description = "CLI tool for Corsair Bragi-protocol devices (HS80, etc.)"
 license = "MIT"