refactor: clean up codebase, remove dead code and obsolete docs

Remove influencer-era documentation, unused components, boilerplate
assets, and ghost tiktok cron job. Add supplier invoice management,
document API routes, and PWA icons. Replace boilerplate README.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/api/banking/sync/route.ts

@@ -43,7 +43,7 @@ export async function POST(request: Request) {
   }
 
   try {
-    const accounts = (connection.accounts as StoredAccount[] || []).map(a => ({ ...a }))
+    const accounts = (connection.accounts_data as StoredAccount[] || []).map(a => ({ ...a }))
 
     const toDate = new Date().toISOString().split('T')[0]
     const fromDate = new Date(Date.now() - days_back * 24 * 60 * 60 * 1000)
@@ -72,7 +72,7 @@ export async function POST(request: Request) {
     await supabase
       .from('bank_connections')
       .update({
-        accounts,
+        accounts_data: accounts,
         last_synced_at: syncedAt,
       })
       .eq('id', connection.id)