fix(windows): skip qmt key lifecycle for disabled broker provider

[Atlas2005]

Summary

Fixes Windows runtime bootstrap so that a disabled QMT provider does not
initialize, validate, read, or modify the retained QMT account-binding key.

When broker_provider=none:

• QMT key initialization is skipped
• QMT key validation is skipped
• QMT key ACLs are not modified
• Existing QMT configuration and key files are preserved
• Missing or corrupt retained QMT keys do not block non-QMT runtime startup

When broker_provider=qmt_builtin_bridge, the existing strict key lifecycle
remains unchanged.

Root cause

bootstrap_windows_runtime_v1.ps1 previously called
Assert-QPAccountBindingKeyState and Initialize-QPAccountBindingKey
unconditionally.

On a machine with a retained historical QMT key, this reached Set-Acl,
which required SeSecurityPrivilege and terminated bootstrap even though
the effective provider was none.

Changes

• Guard QMT key preflight with the resolved provider
• Guard QMT key provisioning with the persisted provider
• Add regression coverage for:
  • provider=none with an existing retained key
  • provider=none with a missing key
  • provider=none with a corrupt retained key
  • preservation of QMT configuration, key bytes, and ACL

Validation

macOS

• Runtime tests: 24 passed, 5 skipped
• Full suite: 1895 passed, 6 skipped
• compileall: passed
• git diff --check: passed

Windows real-machine validation

• Targeted hotfix tests: 2 passed, 27 deselected
• Bootstrap with -BrokerProvider none: passed
• No Set-Acl or SeSecurityPrivilege failure
• PostgreSQL: reachable and healthy
• Grafana: reachable
• Runtime Doctor: passed
• Persisted broker provider: none
• Historical QMT key existence: unchanged
• Historical QMT key SHA256: unchanged

Scope

No changes to:

• TDX signal bridge
• trading logic
• orders
• account state
• PaperTrade accounting
• QMT enabled-provider security behavior
• Docker Compose definitions