Add debug CSV tables showing before/after values for each override

- Writes output/<mod>/debug_ammo.csv and debug_armor.csv
- Columns: classname, source_mod, field, old_value, new_value
- Helps verify rebalance changes make sense

scripts/generate_patches.py

@@ -449,6 +449,7 @@ class AmmoOverride:
     classname: str
     source_mod: str
     changes: dict = field(default_factory=dict)
+    originals: dict = field(default_factory=dict)
 
 
 @dataclass
@@ -457,6 +458,7 @@ class ArmorOverride:
     source_mod: str
     item_type: str
     changes: dict = field(default_factory=dict)
+    originals: dict = field(default_factory=dict)
 
 
 def find_ammo_overrides(
@@ -472,11 +474,13 @@ def find_ammo_overrides(
 
         base = baseline[key]
         changes = {}
+        originals = {}
         for field_name in AMMO_FIELDS:
             mod_val = getattr(e, field_name)
             base_val = getattr(base, field_name)
             if mod_val != base_val and mod_val != 0:
                 changes[field_name] = base_val
+                originals[field_name] = mod_val
 
         # Check ACE array fields (compare as strings)
         for array_field in ["ace_bc", "ace_mv", "ace_bl", "ace_vb"]:
@@ -484,12 +488,14 @@ def find_ammo_overrides(
             base_val = getattr(base, array_field)
             if mod_val != base_val and mod_val not in ("[]", ""):
                 changes[array_field] = base_val
+                originals[array_field] = mod_val
 
         if changes:
             overrides.append(AmmoOverride(
                 classname=e.classname,
                 source_mod=e.source_mod,
                 changes=changes,
+                originals=originals,
             ))
 
     return overrides
@@ -508,6 +514,7 @@ def find_armor_overrides(
 
         base = baseline[key]
         changes = {}
+        originals = {}
         for field_name in ARMOR_FIELDS:
             mod_val = getattr(e, field_name)
             base_val = getattr(base, field_name)
@@ -516,6 +523,7 @@ def find_armor_overrides(
                 continue
             if mod_val != base_val:
                 changes[field_name] = base_val
+                originals[field_name] = mod_val
 
         if changes:
             overrides.append(AmmoOverride(
@@ -523,11 +531,13 @@ def find_armor_overrides(
                 source_mod=e.source_mod,
                 item_type=e.item_type,
                 changes=changes,
+                originals=originals,
             ) if hasattr(AmmoOverride, 'item_type') else ArmorOverride(
                 classname=e.classname,
                 source_mod=e.source_mod,
                 item_type=e.item_type,
                 changes=changes,
+                originals=originals,
             ))
 
     return overrides
@@ -684,6 +694,42 @@ def write_unmatched(
           f"{len(unmatched_armor)} unmatched armor to {out_path}")
 
 
+def write_debug_csvs(
+    mod: str,
+    ammo_overrides: list[AmmoOverride],
+    armor_overrides: list[ArmorOverride],
+):
+    """Write per-mod debug CSVs showing old -> new values for each override."""
+    mod_dir = OUTPUT_DIR / mod
+
+    if ammo_overrides:
+        path = mod_dir / "debug_ammo.csv"
+        with open(path, "w", encoding="utf-8", newline="") as f:
+            writer = csv.writer(f, delimiter=";")
+            writer.writerow(["classname", "source_mod", "field",
+                             "old_value", "new_value"])
+            for o in sorted(ammo_overrides, key=lambda x: x.classname):
+                for field_name in sorted(o.changes.keys()):
+                    old_val = o.originals.get(field_name, "")
+                    new_val = o.changes[field_name]
+                    writer.writerow([o.classname, o.source_mod,
+                                     field_name, old_val, new_val])
+
+    if armor_overrides:
+        path = mod_dir / "debug_armor.csv"
+        with open(path, "w", encoding="utf-8", newline="") as f:
+            writer = csv.writer(f, delimiter=";")
+            writer.writerow(["classname", "source_mod", "item_type",
+                             "field", "old_value", "new_value"])
+            for o in sorted(armor_overrides, key=lambda x: x.classname):
+                for field_name in sorted(o.changes.keys()):
+                    old_val = o.originals.get(field_name, "")
+                    new_val = o.changes[field_name]
+                    writer.writerow([o.classname, o.source_mod,
+                                     o.item_type, field_name,
+                                     old_val, new_val])
+
+
 # ============================================================================
 # Main
 # ============================================================================
@@ -790,6 +836,7 @@ def main():
         config_path = mod_dir / "config.cpp"
         with open(config_path, "w", encoding="utf-8") as f:
             f.write(config_cpp)
+        write_debug_csvs(mod, mod_ammo, mod_armor)
         mods_with_overrides.add(mod)
         print(f"  {mod}/config.cpp ({len(mod_ammo)} ammo, {len(mod_armor)} armor)")