Fix additional issues found in deep dive analysis

1. Remove dead code: Broken socket safety check (line 882)
   - The condition [ "\$datadir/socket.mysql" = "/var/lib/mysql/mysql.sock" ]
     would never be true and is redundant (real check exists at line 864)
   - Removed 4 lines of dead code

2. Simplify confirmation logic (line 1660)
   - Was: if [ "\$confirm" = "0" ] || [ "\$confirm" != "y" ]
   - Now: if [ "\$confirm" != "y" ]
   - More readable and clearer intent (only "y" proceeds)

3. Quote unquoted variable in kill command (line 1000)
   - Was: kill -0 \$pid
   - Now: kill -0 "\$pid"
   - Prevents word splitting if PID contains spaces

4. Clarify script flow (line 740-742)
   - Added comment explaining why script exits after show_recovery_options()
   - Helps users understand they must re-run script with new recovery level
   - Prevents confusion about script termination

This is intentional design: show recovery options, user manually selects
level, user re-runs script. This prevents blind escalation through recovery
levels without explicit user approval at each step (safety consideration).

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

modules/backup/mysql-restore-to-sql.sh

@@ -736,6 +736,11 @@ show_recovery_options() {
         echo "════════════════════════════════════════════════════════════════"
         echo ""
     fi
+
+    # NOTE: After showing recovery options, the script will exit and user must
+    # re-run it with the selected recovery level in Step 4.
+    # This is intentional to avoid automatic retries with different recovery levels
+    # which could cause data corruption if blindly escalating through levels.
 }
 
 # Check available disk space (CRITICAL SAFETY CHECK #3)
@@ -878,12 +883,6 @@ start_second_instance() {
         return 1
     fi
 
-    # Verify using custom socket (not live MySQL socket)
-    if [ -S "/var/lib/mysql/mysql.sock" ] && [ "$datadir/socket.mysql" = "/var/lib/mysql/mysql.sock" ]; then
-        print_error "CRITICAL: Attempting to use live MySQL socket!"
-        return 1
-    fi
-
     # Display isolation confirmation
     echo ""
     print_success "Safety checks passed:"
@@ -998,7 +997,7 @@ start_second_instance() {
     done
 
     # Check if process is still running
-    if ! kill -0 $pid 2>/dev/null; then
+    if ! kill -0 "$pid" 2>/dev/null; then
         print_error "Second MySQL instance failed to start"
         echo ""
 
@@ -1660,10 +1659,10 @@ step5_create_dump() {
     print_warning "Your live MySQL instance will NOT be affected."
 
     echo ""
-    echo -n "Proceed with dump creation? (y/n, or 0 to cancel): "
+    echo -n "Proceed with dump creation? (y/n): "
     read -r confirm
 
-    if [ "$confirm" = "0" ] || [ "$confirm" != "y" ]; then
+    if [ "$confirm" != "y" ]; then
         echo "Operation cancelled."
         press_enter
         exit 0