fix(windows): check Docker Desktop disk space, not only INSTALL_DIR

[Dario-PC-and-Gaming]

Summary

• Windows preflight measured free space only on -InstallDir. Compose image pulls still go into Docker Desktop's WSL VHDX, which is usually on C:. A D: install can pass 25 GB free on D: and then stall or fail while pulling Open WebUI.
• Fail (phase 01) / warn (phase 04) when that Docker data drive is different from the install drive and has under 12 GB free. Keep the existing INSTALL_DIR check for models and config.
• Stop telling users to rerun with -InstallDir C:\ods when they already chose another drive. Explain that models go to the install drive and images stay on Docker's disk.

AI Assistance

Cursor Agent drafted the disk-path helpers, preflight/requirements wiring, tests, and this PR text. I reviewed the diff and ran the focused Windows tests on the machine that hit the failure.

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

Stable hotfix reason:

N/A — mainline Windows preflight fix.

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: High (Windows installer preflight / host mutation gate)
• Validation run:
  • git diff --check
  • Markdown/link sanity for docs
  • Focused tests listed below
  • Dashboard lint/test/build
  • Extension audit / compose validation
  • Release-grade fleet or scoped hardware validation
  • Stable-lane patch validation, if targeting release/2.6.x
  • Not required because:

Commands/results:

powershell.exe -File ods/tests/test-windows-docker-disk-preflight.ps1
  test-windows-docker-disk-preflight: ok

bash tests/test-windows-docker-disk-preflight.sh
  test-windows-docker-disk-preflight: ok

Live Windows (INSTALL_DIR=D:\ods, Docker VHDX on C:):
  Get-WindowsDockerDataPath -> C:\Users\<user>\AppData\Local\Docker\wsl\disk\docker_data.vhdx
  Test-WindowsDockerImageDiskSpace -RequiredGB 12 -> SameAsInstall=False, FreeGB=2, Sufficient=False
  This is the split-drive failure that previously passed preflight and then hung on Open WebUI pull.

Operational Change Check

• This is not an operational change.
• This is an operational change and validation is recorded above.
• This is an operational change and validation is intentionally deferred for:

Notes For Reviewers

• Rollback: revert this PR. Existing installs are unaffected until the Windows installer is re-run.
• Same-drive installs do not add a second quota; the existing INSTALL_DIR 20 GB check still applies.
• Corrupt Docker settings.json / settings-store.json falls back to the default VHDX path instead of aborting preflight.
• Out of scope: SearXNG missing when -NoRecommended still leaves Open WebUI web search enabled. That is a separate installer/service-plan bug.

Made with Cursor