Publish update manifest endpoint for manual update checker

[angnuoli]

Background

PR #45 adds the MicroClaw Desktop client-side manual update checker in Settings > About. The client expects a public update manifest at:

https://microclaw.microsoftol.com/releases/latest.json

That remote endpoint is not available yet, so the checker currently fails safely with the "Could not check for updates" state until the web/CDN side is published.

Scope

• Publish latest.json at the expected URL, or confirm the final manifest URL and update the client constant if it changes.
• Point downloadUrl to the current release artifact, initially likely MicroClawInstaller.zip until a formal MicroClawSetup.exe exists.
• Ensure the manifest is served as JSON over HTTPS.
• Keep the manifest format compatible with the client validation in PR Add manual update checker #45.

Expected manifest shape

{
  "version": "1.0.1",
  "releasedAt": "2026-07-15",
  "downloadUrl": "https://microclaw.microsoftol.com/downloads/MicroClawInstaller.zip",
  "sha256": "<artifact sha256>",
  "openclawVersion": "2026.3.12",
  "releaseNotes": [
    "Add manual update checker"
  ]
}

Acceptance criteria

• GET https://microclaw.microsoftol.com/releases/latest.json returns HTTP 200 with valid JSON.
• version is a numeric dotted version string, for example 1.0.1.
• downloadUrl is HTTPS and points to a downloadable release artifact.
• MicroClaw Desktop Settings > About > Check for updates can show either "up to date" or "update available" instead of failing due to a missing endpoint.

Related

• PR Add manual update checker #45