Adopt Build 2026 Windows setup model via winget configure + selective WindowsDeveloperConfig integration

[Copilot]

This updates the repo’s Windows setup path to the Build 2026 model by moving from imperative winget install commands to a declarative winget configure file. It also adopts WindowsDeveloperConfig selectively (WSL Comfort + language workloads) while explicitly not adopting the full workstation baseline.

• Windows provisioning moved to declarative config

  • Added windows/setup.winget as the primary Windows install entrypoint.
  • Encodes the existing core package baseline in a single idempotent config.

• Build 2026 package/workload additions

  • Added Microsoft.Coreutils.
  • Added language workloads aligned to WindowsDeveloperConfig:
    • Node.js LTS + global TypeScript
    • Python 3.13 + uv
    • .NET SDK 10
    • Rust via rustup (stable toolchain)
    • Go

• Selective WindowsDeveloperConfig adoption documented

  • README now calls out the intended strategy: skip full upstream windows-dev-config/dev-config.winget, adopt WSL Comfort and workloads selectively.
  • Added explicit WSL Comfort clone/run example and positioned it as optional alongside existing bootstrap flow.

• README install flow updated

  • Windows section now presents winget configure as the primary path.
  • Existing manual winget install commands remain as fallback/reference.
  • Updated backlog note to reflect Go coverage via workload config.

winget configure --enable
winget configure -f .\windows\setup.winget --accept-configuration-agreements --disable-interactivity