Add documentation for layout generator functions

Added comprehensive docstrings for chassis layout functions:
- generate_10bay_layout(): Sliger CX4712 10-bay chassis
- generate_micro_layout(): Micro SBC (ZimaBoard) layout
- generate_large1_layout(): Rosewill RSV-L4500U 15-bay chassis

Each docstring includes:
- Brief description of what the layout shows
- Arguments with descriptions
- Side effects (build_drive_map call)

Also fixed inconsistent variable quoting in functions.

Fixes: #20

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

driveAtlas.sh

@@ -293,12 +293,23 @@ check_dependencies() {
 check_dependencies
 
 #------------------------------------------------------------------------------
-# Chassis Type Definitions
+# Chassis Layout Generator Functions
 # These define the physical layout and display formatting for each chassis type
 #------------------------------------------------------------------------------
 
+#------------------------------------------------------------------------------
+# generate_10bay_layout
+#
+# Generates ASCII art representation of a 10-bay hot-swap chassis (Sliger CX4712).
+# Shows storage controllers, M.2 NVMe slot, and 10 front hot-swap bays.
+#
+# Args:
+#   $1 - Hostname to display in the layout header
+#
+# Side effects: Calls build_drive_map() to populate DRIVE_MAP
+#------------------------------------------------------------------------------
 generate_10bay_layout() {
-    local hostname=$1
+    local hostname="$1"
     build_drive_map
 
     # Fixed width for consistent box drawing (fits device names like "nvme0n1")
@@ -349,8 +360,19 @@ generate_10bay_layout() {
     printf "└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘\n"
 }
 
+#------------------------------------------------------------------------------
+# generate_micro_layout
+#
+# Generates ASCII art representation of a micro SBC (e.g., ZimaBoard).
+# Shows storage controllers, onboard eMMC (if present), and 2 SATA ports.
+#
+# Args:
+#   $1 - Hostname to display in the layout header
+#
+# Side effects: Calls build_drive_map() to populate DRIVE_MAP
+#------------------------------------------------------------------------------
 generate_micro_layout() {
-    local hostname=$1
+    local hostname="$1"
     build_drive_map
 
     # Check for eMMC storage
@@ -384,8 +406,19 @@ generate_micro_layout() {
     printf "└─────────────────────────────────────────────────────────────┘\n"
 }
 
+#------------------------------------------------------------------------------
+# generate_large1_layout
+#
+# Generates ASCII art representation of a large1 chassis (Rosewill RSV-L4500U).
+# Shows storage controllers, 2 M.2 NVMe slots, and 15 front bays in 3x5 grid.
+#
+# Args:
+#   $1 - Hostname to display in the layout header
+#
+# Side effects: Calls build_drive_map() to populate DRIVE_MAP
+#------------------------------------------------------------------------------
 generate_large1_layout() {
-    local hostname=$1
+    local hostname="$1"
     build_drive_map
 
     # large1 has 3 stacks of 5 bays at front (15 total) + 2 M.2 slots