Initial commit: InvenTree Stock Tool v2

A comprehensive barcode scanning application for InvenTree inventory management.

Features:
- Multi-mode operation (Add/Update/Check/Locate stock)
- Smart duplicate prevention when adding stock
- Barcode scanning with automatic part code cleaning
- Real-time server connection monitoring
- Part information display with images
- Debug mode for troubleshooting

Fixes applied:
- Fixed encoding issues with non-ASCII characters in barcodes
- Fixed API response handling for list and dict formats
- Implemented duplicate prevention using PATCH to update existing stock
- Added comprehensive error handling and logging

Includes test suite for verification of all fixes.

test_parse_fix.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+"""Test script to verify parse_scan fix for encoding issues."""
+
+from typing import Tuple, Optional
+import re
+
+SEP_RE = re.compile(r'[\x1D\x1E]')
+
+def parse_scan(raw: str) -> Tuple[Optional[str], Optional[int]]:
+    """
+    Parse scanned barcode to extract part code and quantity.
+
+    Args:
+        raw: Raw barcode string
+
+    Returns:
+        Tuple of (part_code, quantity) or (None, None) if parsing fails
+    """
+    def clean_part_code(code: str) -> str:
+        """Clean part code by removing non-ASCII and invalid characters."""
+        # Keep only ASCII printable characters (excluding control chars)
+        # This removes characters like ¡­ and other encoding artifacts
+        cleaned = ''.join(char for char in code if 32 <= ord(char) <= 126)
+        return cleaned.strip()
+
+    # Handle JSON-like format
+    if raw.startswith('{') and '}' in raw:
+        content = raw.strip()[1:-1]
+        part = None
+        qty = None
+
+        for kv in content.split(','):
+            if ':' not in kv:
+                continue
+            k, v = kv.split(':', 1)
+            key = k.strip().upper()
+            val = v.strip()
+
+            if key == 'PM':
+                part = clean_part_code(val)
+            elif key == 'QTY':
+                try:
+                    qty = int(val)
+                except ValueError:
+                    pass
+        return part, qty
+
+    # Handle separator-based format
+    part = None
+    qty = None
+    fields = SEP_RE.split(raw)
+
+    for f in fields:
+        if not f:
+            continue
+        if f.startswith('30P'):
+            part = clean_part_code(f[3:])
+        elif f.lower().startswith('1p'):
+            part = clean_part_code(f[2:])
+        elif f.lower().startswith('q') and f[1:].isdigit():
+            qty = int(f[1:])
+
+    return part, qty
+
+
+# Test with the provided scan data
+test_scan = "{pbn:PICK251017100019,on:WM2510170196,pc:C18548292,pm:STHW4-DU-HS24041¡­,qty:150,mc:,cc:1,pdi:180368458,hp:null,wc:JS}"
+
+print("Testing parse_scan with problematic barcode data:")
+print(f"Input: {test_scan}")
+print()
+
+part, qty = parse_scan(test_scan)
+
+print(f"Parsed part code: '{part}'")
+print(f"Parsed quantity: {qty}")
+print()
+
+# Verify the fix
+expected_part = "STHW4-DU-HS24041"
+expected_qty = 150
+
+if part == expected_part and qty == expected_qty:
+    print("✅ SUCCESS! Part code is correctly parsed.")
+    print(f"   Expected: '{expected_part}'")
+    print(f"   Got:      '{part}'")
+else:
+    print("❌ FAILURE! Parse result doesn't match expected values.")
+    print(f"   Expected part: '{expected_part}', Got: '{part}'")
+    print(f"   Expected qty: {expected_qty}, Got: {qty}")
+
+# Show character codes for verification
+print("\nCharacter analysis of parsed part code:")
+for i, char in enumerate(part or ""):
+    print(f"  [{i}] '{char}' (ASCII {ord(char)})")