5.11 Instance configuration

# 5.11 Instance configuration

**Parent:** Story 5 (#7232)
**Tool file:** new `forge/ee/lib/mcp/tools/instanceConfig.js`

## Summary

Per-instance configuration surfaces: High Availability, custom hostnames, protected instance, auto-update stack, static file storage, and HTTP bearer tokens. Most are plan-gated (see the per-tool notes); the auto-update-stack routes are not. Non-destructive config surfaces that share an enable/disable/update concept are consolidated into single action tools; file and token deletes are separate tools with `destructiveHint: true`.

Start with forge/ee/lib/mcp/tools/instanceConfig.js and the per-tool notes referenced in Story 5 (#7232). Map the listed configuration surfaces and their plan-gating rules, then verify that the non-destructive actions are consolidated and file/token deletion tools carry destructiveHint: true; completion means all listed surfaces are covered.

Written by the indexing model from the issue text.