fix(installer): honor WHISPER_PORT override in Windows conflict scan

[patil2001]

Summary

The Whisper port-conflict scan hardcoded 9100/9000 and ignored a persisted
WHISPER_PORT value from .env, so a re-install with a custom port could scan
the wrong port and miss a real conflict. Resolve it via Resolve-WindowsODSPort
like the WEBUI entry in the same block, keeping the AMD/9100 default.

AI Assistance

Drafted with an AI coding assistant; reviewed by hand and validated locally.

Release Lane

• Stable hotfix targeting release/2.6.x
• Mainline change targeting main
• Next-minor work targeting the next feature/minor release
• Not sure; reviewer should help classify

Changed Surface

• Docs only
• Tests only
• Dashboard UI
• Dashboard API / host agent
• Installer / bootstrap / lifecycle
• Docker Compose / service manifests
• Model routing / Hermes / capabilities
• Network exposure / auth / proxy
• Dependencies / runtime wiring

Risk And Validation

• Risk level: Low
• Validation run:
  • git diff --check
  • Not required because: narrow change; syntax and diff checks pass locally

Commands/results:

git diff --check clean; bash -n on touched scripts passes

Operational Change Check

• This is an operational change and validation is recorded above.