fix(opencode): skip eager import for disabled local tools

[Astro-Han]

Issue for this PR

Closes #22061

Type of change

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

What does this PR do?

Prevents eager import of disabled repo-local custom tools for the documented local tool shapes.

The change adds a cheap pre-scan in the custom tool registry so OpenCode can skip importing a local tool file when every documented tool ID from that file is already disabled by config. It covers the documented local patterns (export default, direct export const/function) and also respects top-level permission denies.

This keeps the fix narrow to #22061 and avoids changing unrelated dependency install behavior.

How did you verify your code works?

• Ran cd packages/opencode && bun test test/tool/registry.test.ts
• Ran cd packages/opencode && bun typecheck
• Added regression coverage for:
  • disabled default-export local tools
  • disabled direct named-export local tools
  • top-level permission denies

Screenshots / recordings

Not applicable.

Checklist

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

[Astro-Han]

The failing e2e checks do not appear to be caused by this PR. I compared this run with recent dev runs and saw the same timeout pattern on both Linux and Windows there as well. In both cases, the job hangs in packages/apps test:e2e:local flow after the seed-e2e.ts phase, before the app server and Playwright start.