Fixed path mapping persistence and repeated logging issues

- Changed while loop with pipe to readarray with for loop to preserve variable state
- Enhanced path detection to better handle identical structures across mounts
- Added debug logging for path cache hits to trace execution
- Added debug output for processed directories at the end of execution

🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

usr/local/lib/torrent-mover/transmission_handler.sh

@@ -13,18 +13,36 @@ get_destination() {
     
     # Check if path is already in the cache
     if [[ -n "${PATH_CACHE["${source_path}"]+x}" ]]; then
-        echo "${PATH_CACHE["${source_path}"]}"
+        local cached_destination="${PATH_CACHE["${source_path}"]}"
+        log_debug "Using cached destination for ${source_path}: ${cached_destination}"
+        echo "${cached_destination}"
         return
     fi
     
     # Skip recursive path analysis - only log once
     if [[ "${source_path}" =~ ^/mnt/dsnas1/ ]]; then
         # Already in destination format, return as is
+        log_debug "Path already in destination format: ${source_path}"
         PATH_CACHE["${source_path}"]="${source_path}"
         echo "${source_path}"
         return
     fi
     
+    # For paths in dsnas2, check if they map to same structure in dsnas1
+    if [[ "${source_path}" =~ ^/mnt/dsnas2/ ]]; then
+        local dir_suffix="${source_path#/mnt/dsnas2/}"
+        local potential_dest="/mnt/dsnas1/${dir_suffix}"
+        
+        # If the directories match exactly in structure, only on different mounts,
+        # return the source to avoid needless copying
+        if [[ -d "${potential_dest}" ]]; then
+            log_debug "Path maps to same structure on different mount: ${source_path} -> ${source_path}"
+            PATH_CACHE["${source_path}"]="${source_path}"
+            echo "${source_path}"
+            return
+        fi
+    fi
+    
     log_info "Analyzing path: ${source_path}"
     local destination="${DEFAULT_DST}"