CLI: Release and smoke-test catalogue discovery package

[gokhanarkan]

Summary

Publish and verify the first exact CLI/platform package containing the merged runtime search foundation plus the current read-only discovery skill and resource-screen integration.

Parent epic: https://github.com/github/copilot-ecosystem/issues/1230
Runtime PRs: https://github.com/github/copilot-agent-runtime/pull/16668 and https://github.com/github/copilot-agent-runtime/pull/16640

Scope

• Publish an exact prerelease after both runtime PRs merge.
• Verify the platform package contains catalog.search, generated Catalog* types, and the packaged discover-resources skill.
• Exercise search through the packaged executable, not a feature-branch worktree.
• Record the exact version, platform shasums, and SDK dependency input.

Acceptance criteria

• Exact package version and shasums are recorded.
• Built executable returns typed MCP/skill candidates without MethodNotFound or search-unavailable.
• Anonymous search, offline fallback, cancellation, and packaged skill discovery pass smoke tests.
• Plugin discovery and installation are explicitly excluded from this prototype release.
• The package is suitable as the input to SDK generation and App integration.