fix: use paths in delete_files prompt example

[WeAreResilience]

Summary

The tag-mode prompt told the model to call mcp__github_file_ops__delete_files with files. The tool schema and handler expect paths, so the first signed-commit delete fails Zod validation.

This changes the prompt example to paths and adds a test so the example cannot drift back to files.

Fixes #1665

Test plan

• bun test test/create-prompt.test.ts (49 pass)
• bun run typecheck

From RESILIENCE Agentic Solutions.

[WeAreResilience]

Verification against the live delete_files Zod schema (the same shape server.tool registers):

Check	Result
Old prompt payload { files, message }	rejected (paths required)
New prompt payload { paths, message }	accepted
Generated tag-mode example parses the live schema	pass
paths as a string, not an array	rejected
paths present, message omitted	rejected
Extra files key beside valid paths	accepted (unknown keys stripped)
commit_files example still uses files	unchanged
Generated delete_files keys are exactly paths + message	pass

These live in test/delete-files-prompt-schema.test.ts (8 tests). Happy to trim the extra coverage if you would rather keep the PR to the one-word prompt change.