Add release-relay package for managing build and release workflows

[davej]

• Implement GitHub PR creation for new builds
• Add webhook signature validation
• Create staging artifact upload mechanism
• Support build and release JSON management
• Add test fixtures and utility functions for release processing

[semanticdiff-com]

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Changed Files

File	Status
.github/workflows/deploy.yml	0% smaller
.github/workflows/promote.yml	0% smaller
.gitignore	Unsupported file format
desktop-builds.json	0% smaller
package-lock.json	0% smaller
packages/desktop-cdn/package.json	0% smaller
packages/desktop-cdn/src/index.ts	0% smaller
packages/desktop-cdn/src/redirections/applyRedirections.ts	0% smaller
packages/desktop-cdn/src/redirections/getAppRedirections.ts	0% smaller
packages/desktop-cdn/src/redirections/getBuildIdByAppVersion.ts	0% smaller
packages/desktop-cdn/src/redirections/pathUtils.ts	0% smaller
packages/desktop-cdn/src/types.ts	0% smaller
packages/desktop-cdn/wrangler.toml	Unsupported file format
packages/desktop-download-cdn/package.json	0% smaller
packages/desktop-download-cdn/src/getDownloadUrl/getDownloadUrlViaManifest.ts	0% smaller
packages/desktop-download-cdn/wrangler.toml	Unsupported file format
packages/release-new-version/package.json	0% smaller
packages/release-relay/package.json	0% smaller
packages/release-relay/src/addDistributablesToStaging/collectArtifactsFromManifests.ts	0% smaller
packages/release-relay/src/addDistributablesToStaging/fetchBuildJSONs.ts	0% smaller
packages/release-relay/src/addDistributablesToStaging/uploadArtifactsToStaging.ts	0% smaller
packages/release-relay/src/createPR.ts	0% smaller
packages/release-relay/src/index.ts	0% smaller
packages/release-relay/src/newReleaseWebhook.ts	0% smaller
packages/release-relay/src/test/fixtures/1.json	0% smaller
packages/release-relay/src/test/testRelease.ts	0% smaller
packages/release-relay/src/types.ts	0% smaller
packages/release-relay/src/validateWebhookSignature.ts	0% smaller
packages/release-relay/wrangler.toml	Unsupported file format