feat(machine-controller): factory reset host BMC during tenant release

[spydaNVIDIA]

Add a gated, deletion-only FactoryResetBmc sub-state machine to the host platform-config flow so tenant release can proactively clear wedged BMC state (bad/rejected boot order observed on GB200, Grace-Grace, and SMC) before the existing power-cycle / boot-order repair runs.

Related issues

#4759

Type of Change

• Add - New feature or capability
• Change - Changes in existing functionality
• Fix - Bug fixes
• Remove - Removed features or deprecated functionality
• Internal - Internal changes (refactoring, tests, docs, etc.)

Breaking Changes

• This PR contains breaking changes

Testing

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed
• No testing required (docs, internal refactor, etc.)

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_{🕐 Last updated: 2026-08-14 20:28:19 UTC | Commit: 38730ce}

[nv-dmendoza]

LGTM, fixes bug