Remove Apple SSO, keep Google + GitHub only

- Removed Apple from OAuth lib (config, exchange, provider type)
- Removed Apple button from auth page
- Removed Apple tab from setup guide page
- Removed Apple env vars from .env, .env.example, docker-compose.yml
- Removed Apple prompts from setup-sso.sh

scripts/setup-sso.sh

@@ -33,19 +33,11 @@ read -sp "  Client Secret: " GOOGLE_CLIENT_SECRET
 echo ""
 echo ""
 
-# --- Prompt for Apple ---
-echo "── 🍎 Apple Sign In ──"
-read -p "  Service ID   : " APPLE_CLIENT_ID
-read -sp "  Client Secret: " APPLE_CLIENT_SECRET
-echo ""
-echo ""
-
 # --- Confirm ---
 echo "═══════════════════════════════════════════════"
 echo "  Summary:"
 echo "  GitHub:  ${GITHUB_CLIENT_ID:0:10}..."
 echo "  Google:  ${GOOGLE_CLIENT_ID:0:10}..."
-echo "  Apple:   $APPLE_CLIENT_ID"
 echo "═══════════════════════════════════════════════"
 read -p "Apply these credentials and redeploy? (y/N) " CONFIRM
 
@@ -56,13 +48,11 @@ fi
 
 # --- Backup current .env ---
 cp "$ENV_FILE" "$ENV_FILE.backup"
-echo "✓ Backed up .env → .env.backup"
+echo "✓ Backed up .env -> .env.backup"
 
 # --- Remove old OAuth lines if they exist ---
 sed -i '/^GOOGLE_CLIENT_ID=/d' "$ENV_FILE"
 sed -i '/^GOOGLE_CLIENT_SECRET=/d' "$ENV_FILE"
-sed -i '/^APPLE_CLIENT_ID=/d' "$ENV_FILE"
-sed -i '/^APPLE_CLIENT_SECRET=/d' "$ENV_FILE"
 sed -i '/^GITHUB_CLIENT_ID=/d' "$ENV_FILE"
 sed -i '/^GITHUB_CLIENT_SECRET=/d' "$ENV_FILE"
 
@@ -72,8 +62,6 @@ cat >> "$ENV_FILE" << EOF
 # --- OAuth / SSO ---
 GOOGLE_CLIENT_ID="$GOOGLE_CLIENT_ID"
 GOOGLE_CLIENT_SECRET="$GOOGLE_CLIENT_SECRET"
-APPLE_CLIENT_ID="$APPLE_CLIENT_ID"
-APPLE_CLIENT_SECRET="$APPLE_CLIENT_SECRET"
 GITHUB_CLIENT_ID="$GITHUB_CLIENT_ID"
 GITHUB_CLIENT_SECRET="$GITHUB_CLIENT_SECRET"
 EOF