fix(skill): recover malformed skill names

[thesobercoder]

Issue for this PR

Closes #21279

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

The skill tool previously required an exact skill name match, so malformed model output like "}rpa-vision " failed even when rpa-vision existed.

This retries lookup with a trimmed and cleaned name when the exact lookup misses, then uses the resolved canonical skill name for permission checks. It keeps the change local to the skill tool and adds a regression test for the reported case.

How did you verify your code works?

• cd packages/opencode && bun test test/tool/skill.test.ts
• cd packages/opencode && bun typecheck
• cd packages/opencode && bun test

Screenshots / recordings

N/A

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[thesobercoder]

The failing unit (linux) check looks unrelated to this PR.

The only failing test is memory: abort controller leak > webfetch does not leak memory over many invocations, which is outside the skill tool area touched here.

This PR only changes:

• packages/opencode/src/tool/skill.ts
• packages/opencode/test/tool/skill.test.ts

I reran the memory test locally with:
cd packages/opencode && bun test test/memory/abort-leak.test.ts

It passed locally with memory growth at 2.88 MB, below the test threshold.

This looks more like a flaky Linux memory check than a regression from this change.