[cris7ian]

Summary

Three targeted simplifications from a code-review pass on src/index.ts, with no behavior change in the common path:

• Flat extension label dedup. Replaces the path-suffix disambiguation walk in listResolvedExtensions with a flat rule: unique label → label; duplicate → scope:label; still duplicate → scope + full path. Duplicate labels are rare, and the old fallback already degraded to a full path.
• Tighter width table. Moves the East-Asian/emoji ranges into a WIDE_RANGES table and drops the per-character combining-mark/zero-width regex. Combining marks now approximate to one column, which can only wrap slightly early — never overflow.
• Shared skills section builder. /context skills and the default view now use one addSkillsSection helper parameterized by cap instead of two copies of the same construction.

Net −8 lines in src/index.ts; the suffix-walk branch was the hardest-to-test code in the file and is gone.

Trade-offs

• Combining marks and variation selectors count as one column instead of zero (minor, conservative direction).
• Same-scope duplicate extension labels now show the full path immediately instead of a searched suffix.

Verification

• npm test — 35/35 pass
• npm run typecheck — clean