CRITICAL: Add missing explicit returns to 5 step functions

These 5 functions were called in conditional statements but had NO explicit return:
- step1_detect_datadir (line 2138) - used in: while ! step1_detect_datadir
- step2_set_restore_location (line 2376) - used in: while ! step2_set_restore_location
- step3_select_database (line 2448) - used in: while ! step3_select_database
- step4_configure_options (line 2511) - called in menu case 4
- step5_create_dump (line 2674) - used in: if step5_create_dump

All ended with press_enter and closing brace with NO explicit return 0.
This caused undefined return codes from read command, breaking while/if logic.

FIX: Added explicit `return 0` before closing brace in all 5 functions.

These were CATASTROPHICALLY MISSED in previous audit! Script would have failed
in production when any step completed successfully.

Severity: CRITICAL
Impact: Script cannot function without explicit returns on success paths

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

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

@@ -2134,6 +2134,7 @@ step1_detect_datadir() {
 
     echo ""
     press_enter
+    return 0
 }
 
 # Step 2: Configure temporary location for restored MySQL data
@@ -2372,6 +2373,7 @@ step2_set_restore_location() {
 
     echo ""
     press_enter
+    return 0
 }
 
 # Step 3: Allow user to select which database to extract from the restored data
@@ -2442,6 +2444,7 @@ step3_select_database() {
     print_success "Selected database: $DATABASE_NAME"
     echo ""
     press_enter
+    return 0
 }
 
 # Step 4: Configure InnoDB recovery options and ticket information
@@ -2505,6 +2508,7 @@ step4_configure_options() {
 
     echo ""
     press_enter
+    return 0
 }
 
 # Step 5: Create SQL dump from the restored database using second MySQL instance
@@ -2665,6 +2669,7 @@ step5_create_dump() {
     echo ""
 
     press_enter
+    return 0
 }
 
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