B2BEA.org Rebuild build-execution S-53

• Added /assets/js/supabase-init.js to initialize browser Supabase clients from script data attributes.
• Replaced repeated inline window.sb createClient blocks in base, admin, studio, and auth layouts.
• Preserved base/auth window.ENV exposure and Studio window.ccos2 initialization through data attributes.
• Added focused Supabase init governance coverage.

• Red test first: node --test test/supabaseInitRuntime.test.js failed before /assets/js/supabase-init.js was wired.
• node --check src/assets/js/supabase-init.js: passed
• node --test test/supabaseInitRuntime.test.js: 1/1 passed
• node scripts/audit-css-governance.js: passed
• git diff --check: passed
• npm test: 117/117 passed
• npm run build: Eleventy copied 125 assets and wrote 126 files
• GitHub Actions build: passed in 17s
• Cloudflare Pages: passed

feature/b2bea-slice-53-supabase-init-runtime

https://github.com/b2bea-org/b2bea-website/pull/88

Start Slice 54 from origin/main; continue inline behavior cleanup, likely base Pro access gating or simple inline event handlers, leaving GTM/Tailwind/data bootstrap scripts classified separately.

• Added /assets/js/supabase-init.js to initialize browser Supabase clients from script data attributes.
• Replaced repeated inline window.sb createClient blocks in base, admin, studio, and auth layouts.
• Preserved base/auth window.ENV exposure and Studio window.ccos2 initialization through data attributes.
• Added focused Supabase init governance coverage.

Start Slice 54 from origin/main; continue inline behavior cleanup, likely base Pro access gating or simple inline event handlers, leaving GTM/Tailwind/data bootstrap scripts classified separately.

Machine-readable source fields