Trigger surface cleanup

Patch release focused on skill triggering — descriptions, hook behavior, and a stale dependency in the package manifest. No public API change.

Changed

• Skill triggering uses the standard mechanism (SKILL.md description) as the single source of truth. Descriptions trimmed to ~230 chars on average (down from ~700) and rewritten in the canonical "what it does + use-when + chain hints" pattern that the rest of the Claude Code skill ecosystem uses. Modern models generalize from one phrase per language, so the keyword-inflated form was paying maintenance cost without measurable trigger gain.
• Skill descriptions now ship Japanese and Traditional Chinese trigger examples alongside Korean and English (omd-apply, omd-init, omd-harness, omd-remember, omd-learn, omd-sync, omd-add-reference). About half of OmD users work in JP / TW, so they previously fell back to weaker description-only matching with English/Korean phrases.
• .claude/hooks/skill-activation.cjs simplified from a keyword/regex forced-eval injector to a DESIGN.md existence gate. The "OMD SKILL ACTIVATION CHECK" block no longer appears on every UI prompt — the hook is silent unless DESIGN.md is missing and the prompt looks like UI work, in which case it surfaces a single one-line nudge to run omd:init first. The forced-eval layer was a custom belt-and-suspenders pattern from the 3.x model era; with 4.x description matching it became overlap and a second source of truth that drifted.

Removed

• .claude/skills/skill-rules.json (dual source-of-truth for the forced-eval matcher).
• Dangling reference to that file in package.json files[].