Fix Cloudflare bridge project isolation check

[maruson08]

Root cause

The first post-merge bridge run stopped before upload because the Pages project API can include the project-owned stable pages.dev subdomain in its domains collection. The isolation check treated every listed domain as a custom domain.

Fix

• exclude the exact project-owned secure-tools-web-bridge.pages.dev subdomain when counting custom domains
• continue requiring zero other domains, main, Direct Upload mode, and disabled Web Analytics
• log only safe project state fields and counts; no credential values
• retain every deployment, route, asset, and noindex gate

Validation

• node tests/run-all.mjs passes
• git diff --check passes
• only the bridge workflow and its contract test change

Refs #67