feat: pzmm conflict detection + content-type categorization

- mod_files manifest table populated at parse time
- POST /api/conflicts endpoint
- mod_types fingerprinting feeds derive_category
- DD filelist regex broadened to cover conflict-eligible exts
- media/maps/<*>/* excluded from manifest (per-mod namespaced,
  no conflict value, can be tens of MB per mod)

Plan: docs/plans/2026-05-04-pzmm-conflict-and-typing.md

api/categorize.py

@@ -0,0 +1,58 @@
+"""Public helper for mapping pzmm content-type tags to sortof CATEGORY_ORDER.
+
+The same mapping is also inlined in `mlos_sort.py` (both api/ and worker/
+copies, deliberately — worker uses a separate venv with no FastAPI deps,
+so it cannot import from api/). This module exposes the helper for
+non-mlos consumers (e.g. /api/conflicts diagnostics output) without
+forcing them to drag in the whole sorter module.
+
+Source: pzmm core/mods.py:detect_mod_types ordering, mapped to sortof's
+CATEGORY_ORDER buckets per docs/plans/2026-05-04-pzmm-conflict-and-typing.md
+§3.4.
+"""
+
+from __future__ import annotations
+
+from typing import Dict, List, Optional
+
+# Items / Animations / Lua / Unknown intentionally absent — too generic to
+# drive a category decision; callers should fall through to other heuristics.
+_TYPE_TO_CAT: Dict[str, str] = {
+    "Maps":         "map",
+    "Vehicles":     "vehicle",
+    "Weapons":      "weapon",
+    "Clothing":     "wearable",
+    "Traits":       "code",
+    "Professions":  "profession",
+    "Recipes":      "crafting",
+    "Tiles":        "tile",
+    "Textures":     "texture",
+    "Sounds":       "sound",
+    "UI":           "ui",
+    "Translations": "translation",
+    "Patch":        "patch",
+    "Dependency":   "tweaks",
+    "Framework":    "tweaks",
+}
+
+
+def types_to_category(mod_types: List[str], name: str = "") -> Optional[str]:
+    """First mod_type that maps to a sortof CATEGORY_ORDER bucket wins.
+
+    Returns the bucket name (e.g. "weapon", "vehicle"), or None when:
+      - mod_types is empty (manifest not yet built), or
+      - mod_types contains only skip-types (Items / Animations / Lua / Unknown).
+
+    The `name` arg is used for the vehicle_spawn refinement only — when a
+    Vehicles-tagged mod is named like "spawn zone X", the more specific
+    `vehicle_spawn` bucket wins over the generic `vehicle`.
+    """
+    if not mod_types:
+        return None
+    for t in mod_types:
+        cat = _TYPE_TO_CAT.get(t)
+        if cat:
+            if cat == "vehicle" and name and "spawn zone" in name.lower():
+                return "vehicle_spawn"
+            return cat
+    return None