Add comprehensive documentation for all 20 functions

Documentation Coverage:
- Total functions: 20
- Previously documented: 13
- Now documented: 20 (100% coverage)

Added Function Descriptions:
- show_intro: Script overview banner
- step1_detect_datadir: Auto-detect/prompt for MySQL directory
- step2_set_restore_location: Configure temporary restore directory
- step3_select_database: Database selection from restored data
- step4_configure_options: InnoDB recovery and ticket options
- step5_create_dump: SQL dump creation and validation
- main: Orchestrate the 5-step workflow

Each function now includes:
- Clear one-line purpose statement
- Parameter descriptions where applicable
- Key variables set or used
- Main workflow steps

Impact: Significantly improves code maintainability and makes it easier
for new developers to understand the script structure and workflow.

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

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

@@ -1233,6 +1233,8 @@ dump_database() {
 # INTERACTIVE WORKFLOW
 ################################################################################
 
+# Display the welcome banner and script overview to the user
+# Explains what the script does and shows required steps
 show_intro() {
     clear
     print_banner "MySQL/MariaDB File-Based Restore"
@@ -1290,6 +1292,9 @@ show_intro() {
     echo ""
 }
 
+# Step 1: Auto-detect or prompt for live MySQL data directory
+# Looks for running MySQL instance or attempts to find config file
+# Sets LIVE_DATADIR variable for use in later steps
 step1_detect_datadir() {
     print_banner "Step 1: Detect Live MySQL Data Directory"
 
@@ -1341,6 +1346,10 @@ step1_detect_datadir() {
     press_enter
 }
 
+# Step 2: Configure temporary location for restored MySQL data
+# Allows user to choose suggested directory or provide custom path
+# Validates path for safety (no traversal, not live MySQL dir)
+# Sets TEMP_DATADIR variable for second MySQL instance
 step2_set_restore_location() {
     print_banner "Step 2: Set Restored Data Location"
 
@@ -1575,6 +1584,10 @@ step2_set_restore_location() {
     press_enter
 }
 
+# Step 3: Allow user to select which database to extract from the restored data
+# Lists available databases from TEMP_DATADIR and prompts for selection
+# Validates database directory exists before proceeding
+# Sets DATABASE_NAME variable for dump operation
 step3_select_database() {
     print_banner "Step 3: Select Database to Restore"
 
@@ -1641,6 +1654,10 @@ step3_select_database() {
     press_enter
 }
 
+# Step 4: Configure InnoDB recovery options and ticket information
+# Allows user to set InnoDB force recovery level if needed (0-6)
+# Prompts for optional ticket number for tracking purposes
+# Shows analysis-based recovery recommendations from error logs
 step4_configure_options() {
     print_banner "Step 4: Configure Restore Options"
 
@@ -1700,6 +1717,10 @@ step4_configure_options() {
     press_enter
 }
 
+# Step 5: Create SQL dump from the restored database using second MySQL instance
+# Starts isolated MySQL instance, dumps selected database, validates integrity
+# Generates .sql file with optional ticket number in filename
+# Cleans up second instance and provides import instructions
 step5_create_dump() {
     print_banner "Step 5: Create SQL Dump"
 
@@ -1813,6 +1834,10 @@ step5_create_dump() {
 # MAIN EXECUTION
 ################################################################################
 
+# Main entry point: orchestrates the 5-step workflow to extract SQL from restored backup
+# Detects MySQL location, validates restore files, starts second instance,
+# creates SQL dump, and provides usage instructions
+# Handles errors and signal interrupts with proper cleanup
 main() {
     show_intro
     echo -n "Continue? (y/n, or 0 to cancel): "