feat: terminology fix (Entry→Event), diary page generation, settings refactor

- Rename Entry→Event throughout frontend and backend
- Change 'journal' terminology to 'diary page'
- Add professional footer with links
- Redirect to diary page after generation
- Error handling for generation failures
- Fix settings to store per-provider configs in providerSettings
- Backend reads API key from providerSettings
- Use prisma db push instead of migrate for schema sync
- Clean up duplicate entries.ts file

backend/prisma/schema.prisma

@@ -15,7 +15,7 @@ model User {
   updatedAt    DateTime @updatedAt
 
   apiKeys  ApiKey[]
-  entries  Entry[]
+  events   Event[]
   journals Journal[]
   tasks    Task[]
   settings Settings?
@@ -34,7 +34,7 @@ model ApiKey {
   @@index([userId])
 }
 
-model Entry {
+model Event {
   id        String   @id @default(uuid())
   userId    String
   date      String
@@ -56,7 +56,7 @@ model Journal {
   userId      String
   date        String
   content     String
-  entryCount  Int
+  eventCount  Int
   generatedAt DateTime @default(now())
 
   user User @relation(fields: [userId], references: [id], onDelete: Cascade)