Fixes two runtime errors:
1. "Lock 'lock:sb-xxx-auth-token' was released because another request
stole it" — caused by multiple Supabase client instances competing
for the same auth storage lock.
2. "Failed to fetch conversations: {}" — related to #1. When the auth
lock is stolen mid-request, the session becomes temporarily
unavailable and queries fail.
The codebase had 65 call sites invoking createClient() — each creating
a new browser client with its own auth listener. This change makes
createClient() cache and return a single shared instance.
Also improved error logging in conversation-list.tsx to show Supabase
error fields (message/details/hint/code) instead of an empty {}.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Next.js route groups like (dashboard) don't appear in URLs, so the
sidebar, header, and dashboard page were linking to /dashboard/inbox,
/dashboard/contacts, etc. which don't exist and returned 404.
Fixed paths in:
- src/components/layout/sidebar.tsx (nav hrefs)
- src/components/layout/header.tsx (page title map)
- src/app/(dashboard)/dashboard/page.tsx (router.push calls)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>