Add Print Queue UI and slicer post-processing script

- Create Print Queue page showing pending/completed/cancelled jobs
- Add needs_weighing filter to spool API for flagged spools
- Add IPrintJob interface and needs_weighing to ISpool model
- Add slicer_post_process.py for Elegoo/Orca Slicer integration
- Add translations for print queue feature
- Bump version to 0.23C.3

The workflow:
1. Slicer post-processing script creates pending print job
2. After print, user confirms (deducts filament) or cancels (flags for weighing)
3. Spools needing weigh-in are shown in Print Queue UI

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

scripts/slicer_post_process.py

@@ -0,0 +1,214 @@
+#!/usr/bin/env python3
+"""
+Elegoo Slicer / Orca Slicer Post-Processing Script for Spoolman Integration.
+
+This script parses G-code files to extract filament usage information and creates
+a pending print job in Spoolman. After the print completes, use the Spoolman
+Print Queue UI to confirm the print (deducts filament) or cancel it (flags for weighing).
+
+Usage:
+    1. In Elegoo Slicer, go to Printer Settings > Post-processing Scripts
+    2. Add the path to this script: /path/to/slicer_post_process.py
+    3. Configure the environment variables below or create a config file
+
+Configuration:
+    Set these environment variables:
+    - SPOOLMAN_URL: Your Spoolman instance URL (e.g., http://192.168.0.11:8000)
+    - SPOOLMAN_SPOOL_ID: Default spool ID to use (or set per-filament in slicer)
+
+    Or create a file at ~/.config/spoolman/slicer.conf:
+        [spoolman]
+        url = http://192.168.0.11:8000
+        spool_id = 1
+
+The script will:
+    1. Read the G-code file passed as argument
+    2. Parse Elegoo/Orca slicer comments for filament usage
+    3. Create a pending print job in Spoolman via API
+    4. The job appears in the Print Queue for confirmation after printing
+"""
+
+import configparser
+import os
+import re
+import sys
+import urllib.request
+import json
+from pathlib import Path
+
+
+def get_config() -> tuple[str, int]:
+    """Get Spoolman URL and default spool ID from environment or config file."""
+    url = os.environ.get("SPOOLMAN_URL")
+    spool_id = os.environ.get("SPOOLMAN_SPOOL_ID")
+
+    if not url:
+        config_path = Path.home() / ".config" / "spoolman" / "slicer.conf"
+        if config_path.exists():
+            config = configparser.ConfigParser()
+            config.read(config_path)
+            url = config.get("spoolman", "url", fallback=None)
+            spool_id = config.get("spoolman", "spool_id", fallback=None)
+
+    if not url:
+        print("ERROR: SPOOLMAN_URL not set. Set environment variable or create config file.", file=sys.stderr)
+        sys.exit(1)
+
+    if not spool_id:
+        print("ERROR: SPOOLMAN_SPOOL_ID not set. Set environment variable or create config file.", file=sys.stderr)
+        sys.exit(1)
+
+    return url.rstrip("/"), int(spool_id)
+
+
+def parse_gcode(filepath: str) -> dict:
+    """
+    Parse G-code file for filament usage information.
+
+    Looks for Elegoo/Orca Slicer comments like:
+    ; total filament used [g] = 12.34
+    ; filament used [mm] = 4567.89
+    ; filament used [g] = 12.34
+
+    Also checks for PrusaSlicer format:
+    ; filament used [mm] = 4567.89
+    ; filament used [g] = 12.34
+    """
+    result = {
+        "filename": Path(filepath).name,
+        "filament_used_g": None,
+        "filament_used_mm": None,
+    }
+
+    # Patterns for different slicers
+    patterns = {
+        # Elegoo/Orca format
+        "total_filament_g": re.compile(r";\s*total filament used \[g\]\s*=\s*([\d.]+)", re.IGNORECASE),
+        "filament_g": re.compile(r";\s*filament used \[g\]\s*=\s*([\d.]+)", re.IGNORECASE),
+        "filament_mm": re.compile(r";\s*filament used \[mm\]\s*=\s*([\d.]+)", re.IGNORECASE),
+        # Alternative formats
+        "filament_weight": re.compile(r";\s*(?:total )?filament (?:weight|cost)\s*=\s*([\d.]+)\s*g", re.IGNORECASE),
+        "filament_length": re.compile(r";\s*(?:total )?filament\s*=\s*([\d.]+)\s*mm", re.IGNORECASE),
+    }
+
+    try:
+        with open(filepath, "r", encoding="utf-8", errors="ignore") as f:
+            # Only read first 500 lines and last 500 lines for efficiency
+            lines = f.readlines()
+            header = lines[:500]
+            footer = lines[-500:] if len(lines) > 500 else []
+            check_lines = header + footer
+
+            for line in check_lines:
+                if not line.startswith(";"):
+                    continue
+
+                # Check each pattern
+                for key, pattern in patterns.items():
+                    match = pattern.search(line)
+                    if match:
+                        value = float(match.group(1))
+                        if "g" in key or "weight" in key:
+                            if result["filament_used_g"] is None:
+                                result["filament_used_g"] = value
+                        elif "mm" in key or "length" in key:
+                            if result["filament_used_mm"] is None:
+                                result["filament_used_mm"] = value
+
+    except Exception as e:
+        print(f"Warning: Error parsing G-code: {e}", file=sys.stderr)
+
+    return result
+
+
+def create_print_job(url: str, spool_id: int, gcode_info: dict) -> bool:
+    """Create a pending print job in Spoolman."""
+    if gcode_info["filament_used_g"] is None:
+        print("Warning: Could not find filament weight in G-code. Skipping job creation.", file=sys.stderr)
+        return False
+
+    api_url = f"{url}/api/v1/print-job"
+
+    payload = {
+        "spool_id": spool_id,
+        "filename": gcode_info["filename"],
+        "filament_used_g": gcode_info["filament_used_g"],
+    }
+
+    if gcode_info["filament_used_mm"] is not None:
+        payload["filament_used_mm"] = gcode_info["filament_used_mm"]
+
+    try:
+        data = json.dumps(payload).encode("utf-8")
+        req = urllib.request.Request(
+            api_url,
+            data=data,
+            headers={"Content-Type": "application/json"},
+            method="POST",
+        )
+
+        with urllib.request.urlopen(req, timeout=10) as response:
+            if response.status in (200, 201):
+                result = json.loads(response.read().decode("utf-8"))
+                print(f"Created print job #{result['id']}: {gcode_info['filename']} ({gcode_info['filament_used_g']:.1f}g)")
+                return True
+            else:
+                print(f"Error: API returned status {response.status}", file=sys.stderr)
+                return False
+
+    except urllib.error.HTTPError as e:
+        error_body = e.read().decode("utf-8") if e.fp else ""
+        print(f"Error: API request failed: {e.code} {e.reason} - {error_body}", file=sys.stderr)
+        return False
+    except urllib.error.URLError as e:
+        print(f"Error: Could not connect to Spoolman: {e.reason}", file=sys.stderr)
+        return False
+    except Exception as e:
+        print(f"Error: {e}", file=sys.stderr)
+        return False
+
+
+def main():
+    """Main entry point."""
+    if len(sys.argv) < 2:
+        print("Usage: slicer_post_process.py <gcode_file>", file=sys.stderr)
+        print(__doc__)
+        sys.exit(1)
+
+    gcode_path = sys.argv[1]
+
+    if not os.path.exists(gcode_path):
+        print(f"Error: G-code file not found: {gcode_path}", file=sys.stderr)
+        sys.exit(1)
+
+    # Get configuration
+    url, spool_id = get_config()
+
+    # Parse G-code
+    print(f"Parsing G-code: {gcode_path}")
+    gcode_info = parse_gcode(gcode_path)
+
+    if gcode_info["filament_used_g"]:
+        print(f"  Filament: {gcode_info['filament_used_g']:.2f}g", end="")
+        if gcode_info["filament_used_mm"]:
+            print(f" ({gcode_info['filament_used_mm']:.1f}mm)")
+        else:
+            print()
+    else:
+        print("  Warning: Could not parse filament usage from G-code")
+
+    # Create print job
+    success = create_print_job(url, spool_id, gcode_info)
+
+    if success:
+        print(f"Print job created in Spoolman ({url})")
+        print("After printing, use the Print Queue to confirm or cancel the job.")
+    else:
+        print("Failed to create print job. The print will proceed without tracking.", file=sys.stderr)
+
+    # Always exit 0 so the slicer continues with the print
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()