fix(migrate): add account_id to generated wrangler.jsonc template

Problem

The migration script's generateWranglerConfig in packages/blocks-cli/scripts/migrate/phase-scaffold.ts does not include account_id in the generated wrangler.jsonc. Without it, wrangler deploy targets the deploying user's default CF account instead of the deco-cx account — causing Worker-to-Worker fetches to deco-otel-ingest.deco-cx.workers.dev to return 404.

This was observed on miess-01-tanstack: every POST to the otel-ingest endpoint returned 404, while other sites (casaevideo, lebiscuit, baggagio) that had account_id pinned got 200 OK. Fix was applied manually via PR #56 on that site.

Fix

Add account_id: "c95fc4cec7fc52453228d9db170c372c" to the object returned by generateWranglerConfig in packages/blocks-cli/scripts/migrate/phase-scaffold.ts, so every newly migrated site already has the correct account pinned from day one.

Why this account_id

c95fc4cec7fc52453228d9db170c372c is the deco-cx Cloudflare account that hosts deco-otel-ingest and deco-otel-tail. Both Worker-to-Worker fetches and tail_consumers bindings require in-account routing to resolve correctly.

Start in packages/blocks-cli/scripts/migrate/phase-scaffold.ts and inspect generateWranglerConfig. Verify the generated wrangler.jsonc structure and confirm that newly migrated sites pin the specified Cloudflare account_id so Worker-to-Worker routing uses the deco-cx account.