fix(mcp): include tool names in policy logs

[kirit93]

Summary

Adds mcp tool name to openshell sandbox logs

Testing

• mise run pre-commit passes
• Unit tests added/updated

Checklist

• Follows Conventional Commits
• Commits are signed off (DCO)

[johntmyers]

gator-agent

Maintainer Approval Needed

Gator validation and PR monitoring are complete.

Validation: PR #2189 is project-valid as a small, maintainer-authored MCP logging fix scoped to JSON-RPC policy log output.
Head SHA: 03ea5d8b779888ce23e19bd2dab5cb15bd88c525

Review: Independent code review found no critical or warning-level findings. The change keeps tool names sanitized for log output and adds unit coverage for allowed, denied, and non-tool JSON-RPC cases.
Docs: No Fern docs update required; this changes internal policy log detail rather than a documented user workflow or CLI/API contract.
Checks: Required Branch Checks, Helm Lint, DCO, and vouch gates are passing.
E2E: N/A; no test:* label is needed for this log-format-only change.

Human maintainer approval is now required.