fix: substitute variables in keys tool

[ShaoyeLi]

Summary

• pass agent variables into the keys tool just like other variable-aware tools
• substitute %variable% placeholders before typing when method="type"
• cover the regression with a unit test that asserts the resolved value is typed

Testing

• pnpm --dir packages/core run build:esm
• pnpm --dir packages/core exec vitest run dist/esm/tests/unit/agent-execution-model.test.js
• pnpm --dir packages/core exec eslint lib/v3/agent/tools/index.ts lib/v3/agent/tools/keys.ts tests/unit/agent-execution-model.test.ts

---

Summary by cubic

Fixes variable substitution in the keys tool by passing agent variables and resolving %variable% placeholders before typing, preventing literal placeholders from being typed.

• Bug Fixes
  • Wired variables into keys via createAgentTools and substituted values when method="type".
  • Added a unit test to assert %token% resolves and the actual value is typed.

^{Written for commit 1c29e02. Summary will update on new commits. Review in cubic}

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Latest commit: 1c29e02

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[github-actions]

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