Normalize WebSocket bearer tokens

[aiirvizionz]

Summary

• normalize WebSocket Authorization bearer parsing with case-insensitive scheme and flexible spacing
• trim extracted bearer tokens before Supabase auth lookup
• add focused regression tests for spaced/case-insensitive bearer headers and empty bearer query fallback

Tests

• .\node_modules.bin\vitest.CMD run src\lib\websocket\middleware\auth.test.js
• node --check src\lib\websocket\middleware\auth.js
• node --check src\lib\websocket\middleware\auth.test.js
• git diff --check