Allow host-specific view_image policies

[roackb2]

Summary

• add a bounded ViewImageToolOptions.defaultPrompt fallback for view_image calls that omit prompt while preserving the existing coding-assistant default
• add ViewImageToolOptions.sourcePolicy with paths-only, references-only, and paths-and-references modes
• narrow the model-visible JSON parameters and execution validation consistently so disabled locator kinds cannot be invoked
• require a resourceResolver whenever reference inputs are enabled, leaving TA to own authorization/reference resolution while Heddle enforces disabled source kinds

Verification

• yarn vitest run src/tests/integration/tools/tools.test.ts --testNamePattern viewImageTool
• yarn vitest run src/tests/unit/tools/external-context-contracts.test.ts
• yarn tsc -p tsconfig.build.json --noEmit
• yarn lint
• yarn build

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-07T15:49:09.113249Z	77dc076	PR opened

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