fix(config): default omitted model tools capability

[LeoParkerOu]

Issue for this PR

Closes #50340

Type of change

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

What does this PR do?

A configured model may specify input and output capabilities without a tools field. The user-facing config schema previously rejected that provider entry, so it was silently skipped.

This change makes tools optional in the config schema and normalizes an omitted value to false when the provider is loaded. Explicit true and false values remain unchanged. A regression test verifies provider loading and capability preservation.

How did you verify your code works?

• Provider tests pass.
• Full config test suite passes.
• Core typecheck passes.
• Prettier check passes on changed files.

Screenshots / recordings

Not applicable.

Checklist

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

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

I found a potential duplicate PR:

Related PR:

• fix(schema): default omitted capability tools for custom providers #49940 - fix(schema): default omitted capability tools for custom providers

  • fix(schema): default omitted capability tools for custom providers #49940

  This appears to address a very similar issue: making the tools field optional in capability schemas and defaulting omitted values. This may be a prior attempt at fixing the same or related problem.

The current PR #50702 and #49940 both deal with making tools optional and normalizing omitted values in provider/capability configuration. You should verify whether #49940 was merged, closed, or abandoned, and confirm that #50702 isn't duplicating that work.