#1246 Toolkit staged cutover

Steps:

1. Validate the integrated monorepo in getsentry/sentry-mcp — require full CLI/MCP CI, workspace release dry-runs, Cloudflare docs preview, MCP Cloudflare canary, and exact-head correctness/security reviews.
2. Rename to getsentry/toolkit — verify redirects, protections, secrets, environments, GitHub App, webhooks, and Cloudflare wiring; rerun CI, canaries, staging releases, and the upgrade matrix.
3. Dual-publish CLI stable and nightly releases to Toolkit and getsentry/cli — pre-bridge binaries know only legacy endpoints.
4. Archive getsentry/cli only after at least two stable releases, roughly 90 days, and evidence that legacy use ended. Gotchas:

• Renaming before validation risks live MCP deployment wiring.
• Archiving at rename strands legacy upgrades. Verify:
• [ ] Assets, hashes, manifests, from-version, and delta metadata match across mirrors.
• [ ] Binary and installer matrices pass for stable and nightly.