As a Windows operator I can install fallout-agent via winget

[ChrisonSimtian]

Story

As a Windows operator managing a CD target host, I want to install the Fallout deployment agent with a single winget install Fallout.Agent so I get a registered, ready-to-enrol Windows Service without manually unpacking a zip or scripting service registration.

Why

RFC #113 defines fallout-agent as a self-contained executable that operators run on hosts the forge runner can't reach. For Windows fleets, "self-contained executable" is necessary but not sufficient — operators expect a native, signed, package-managed install with a Service entry that survives reboots. winget is Microsoft's default answer and the lowest-friction install path for the target audience.

Acceptance criteria

Sub-tasks (filled in after creation):

• Author winget manifest YAML for fallout-agent #124 — Author winget manifest YAML
• Build signed MSIX installer for fallout-agent #125 — Build signed MSIX installer in release pipeline
• Installer registers FalloutAgent as a Windows Service #126 — Installer registers FalloutAgent Windows Service
• Open automated PR to microsoft/winget-pkgs on stable tag #127 — Open automated PR to microsoft/winget-pkgs on stable tag
• Add Windows smoke test for winget install #128 — Windows smoke test for winget install

Out of scope

• MSIX Store distribution (separate channel; revisit if there's demand).
• ARM64 Windows builds (deferred until x64 is shipping cleanly).
• In-app auto-update — winget upgrade handles upgrade; agent owns no self-update logic in this story.

Related

• RFC [RFC] CD deployment agent/runner — lightweight, forge-agnostic, idle-and-wait #113 — CD deployment agent/runner
• RFC [RFC] Continuous Delivery: Fallout as a release-management platform #106 — Continuous Delivery vision

[ChrisonSimtian]

Tracked under epic #139.