feat: voice-friendly skill triggers for AquaVoice (v0.14.6.0) (#732)

* feat: voice-friendly skill triggers for speech-to-text input

Add voice-triggers YAML field to 10 SKILL.md.tmpl files with natural-language
aliases (e.g. "see-so" for /cso, "tech review" for /plan-eng-review).
gen-skill-docs preprocesses voice triggers before transformFrontmatter,
folding them into the description and stripping the field from output.
Includes unit tests, README voice input section, and CONTRIBUTING.md update.

* chore: bump version and changelog (v0.14.6.0)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>