Zabbix supply backend rebuild + data-driven model supplies

Rewrite the printer Zabbix integration (Bearer auth, host-by-IP, tag-based
supply lookup, ping) and replace the hardcoded toner table with a
modelsupplies table + CRUD + seed. Add mock Zabbix server, live test
harness, and the Playwright screenshot tooling.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plugins/printers/services/supply_parts.py

@@ -0,0 +1,107 @@
+"""Printer supply classification and part-number lookup.
+
+Part numbers now live in the modelsupplies table (see seed_supplies.py),
+managed through the API/UI. This module keeps the runtime logic that is not
+per-model data: classifying a reported level into ok/low/critical (waste
+cartridges invert), deriving supply type and color from a Zabbix item name,
+and reading the matching part numbers out of the database.
+"""
+
+from typing import Dict, List, Optional
+
+
+# alert thresholds (percent remaining)
+CRITICAL_THRESHOLD = 5
+LOW_THRESHOLD = 10
+
+
+def derivesupplytype(name: str) -> str:
+    """Map a Zabbix item name to a supply type."""
+    lowername = (name or "").lower()
+    if "waste" in lowername:
+        return "waste"
+    if "drum" in lowername or "imaging" in lowername:
+        return "drum"
+    if "maintenance" in lowername or "fuser" in lowername:
+        return "maintenance"
+    return "toner"
+
+
+def derivecolor(name: str, tagcolor: Optional[str] = None) -> str:
+    """Best-effort supply color from a Zabbix color tag, then the item name."""
+    color = (tagcolor or "").lower()
+    if "black" in color:
+        return "black"
+    if color in ("cyan", "magenta", "yellow"):
+        return color
+    if color in ("grey", "gray"):
+        return "gray"
+
+    lowername = (name or "").lower()
+    for candidate in ("cyan", "magenta", "yellow", "black"):
+        if candidate in lowername:
+            return candidate
+    return "none"
+
+
+def classifysupply(level: float, name: str, vendor: Optional[str]) -> Dict:
+    """Classify one supply item into ok/low/critical.
+
+    Waste cartridge fill is inverted vs a toner level: a full waste cartridge
+    is bad. Standard vendors report waste as percent FULL (high = bad). Xerox
+    EC/AltaLink series report waste as percent capacity REMAINING (low = bad),
+    same direction as toner. Normalise everything to percent remaining first.
+    """
+    lowername = (name or "").lower()
+    iswaste = "waste" in lowername
+    isdrum = "drum" in lowername or "imaging" in lowername
+    isxerox = bool(vendor) and "xerox" in vendor.lower()
+
+    if iswaste and not isxerox:
+        remaining = 100 - level
+    else:
+        remaining = level
+
+    if remaining <= CRITICAL_THRESHOLD:
+        status = "critical"
+    elif remaining <= LOW_THRESHOLD:
+        status = "low"
+    else:
+        status = "ok"
+
+    return {
+        "status": status,
+        "remaining": round(remaining, 1),
+        "iswaste": iswaste,
+        "isdrum": isdrum,
+    }
+
+
+def lookupsupplies(modelnumberid: Optional[int], color: str,
+                   supplytype: str) -> List[Dict]:
+    """Part-number options for a model + color + supply type, from the DB.
+
+    Returns every matching capacity tier (standard / high / metered / ...) so
+    the report can show all reorder options, like the classic report did.
+    """
+    if not modelnumberid:
+        return []
+
+    from ..models import ModelSupply
+
+    query = ModelSupply.query.filter_by(
+        modelnumberid=modelnumberid,
+        supplytype=supplytype,
+        isactive=True,
+    )
+    # toners are color-specific; drum/waste/maintenance are not
+    if supplytype == 'toner' and color and color != 'none':
+        query = query.filter_by(color=color)
+
+    rows = query.order_by(ModelSupply.capacitytier).all()
+    return [{
+        'partnumber': row.partnumber,
+        'marketingname': row.marketingname,
+        'capacitytier': row.capacitytier,
+        'pageyield': row.pageyield,
+    } for row in rows]