devbench: add discoverable openshaders.menu + section navigation for CS config QA

[Copilot]

Driving the Community Shaders config menu through devbench was under-discoverable (menu invoke name=CommunityShaders only) and not scriptable by section, causing avoidable round-trips before QA could begin. This change surfaces a namespaced menu tool and adds section-aware navigation to support deterministic UI/i18n sweeps.

• Tool surface / discoverability

  • Register new openshaders.menu tool in the Open Shaders namespace.
  • Keep base menu extension (CommunityShaders) and align its schema/description with the new behavior.

• Menu control semantics

  • Extend menu handler to accept optional section.
  • If section is provided and op is omitted, default operation becomes open (instead of toggle).
  • Return payload now includes section when provided.

• Section navigation behavior

  • Route section into menu selection (Menu::SelectFeatureMenu).
  • Expand selection matching to support:
    • built-in pages (Home, General, Advanced, Profiling)
    • feature short names
    • feature display names
  • Matching is normalization-based (case/format tolerant) for robust automation inputs.

• Docs / in-product guidance

  • Add openshaders.menu to Remote Control settings tool list.
  • Update release-validation docs with:
    • openshaders.menu QA example
    • explicit base-tool call: menu {"action":"invoke","name":"CommunityShaders"}

// New namespaced control
{"tool":"openshaders.menu","args":{"op":"open","section":"Advanced"}}

// Base tool remains supported (extension key: CommunityShaders)
{"tool":"menu","args":{"action":"invoke","name":"CommunityShaders","section":"Light Limit Fix"}}