fix(organize): stop keyword-dump tags from becoming folder names (#1119)

CivitAI tags are normally short single-concept labels, but some uploaders
pack their entire keyword list into one tag. The model in #1119 carries
"lora, character, rosie, irish, ... face" as a single 181-character tag.
Priority resolution matches aliases by exact equality, so that tag matched
nothing and resolve_priority_tag_for_model fell back to tags[0] -- the blob.
With the default "{base_model}/{first_tag}" template the model was filed
under "Krea 2/<181-character blob>/", and the full path plus the
".civitai.info" sidecar and the preview images next to it ran into the
Windows MAX_PATH limit.

Tags also bypassed sanitization on the way into a path: both
calculate_relative_path_for_model and DownloadManager._calculate_relative_path
sanitized model_name and version_name but interpolated {first_tag} verbatim,
so a tag containing "/" or ":" silently produced nested or illegal folders.

Two changes:

- The fallback skips tags that cannot serve as a folder name.
  is_usable_path_tag rejects comma-separated keyword dumps and tags longer
  than MAX_PATH_TAG_LENGTH; the resolver returns "" when nothing usable is
  left, which callers already render as "no tags". Whole-tag priority
  matching is untouched, so existing priority configurations behave the
  same.
- sanitize_folder_name gains an optional max_length, and every tag-derived
  segment now goes through it. Tags are capped at MAX_PATH_TAG_LENGTH, model
  and version names at MAX_FOLDER_NAME_LENGTH, and rendered filename stems at
  MAX_FILENAME_STEM_LENGTH.

For the reported model the folder becomes "Krea 2/base model" instead of the
blob, and the full path drops from 235 to 64 characters.

Existing libraries are not migrated up front: a path is only recomputed on
download, on an auto-organize run or when a filename template is applied, and
values already inside the caps are left byte-identical. Models previously
filed under a keyword-dump folder move on the next auto-organize run.

tests/utils/test_utils.py

@@ -2,6 +2,11 @@ import pytest
 
 from py.services.settings_manager import SettingsManager, get_settings_manager
 from py.services.service_registry import ServiceRegistry
+from py.utils.constants import (
+    MAX_FILENAME_STEM_LENGTH,
+    MAX_FOLDER_NAME_LENGTH,
+    MAX_PATH_TAG_LENGTH,
+)
 from py.utils.utils import (
     calculate_filename_for_model,
     calculate_recipe_fingerprint,
@@ -12,6 +17,15 @@ from py.utils.utils import (
 )
 
 
+# Real CivitAI data for the model reported in issue #1119: the uploader dumped
+# a whole keyword list into a single tag.
+KEYWORD_DUMP_TAG = (
+    "lora, character, rosie, irish, redhead, auburn, freckles, green eyes, "
+    "curly hair, woman, female, photorealistic, realistic, krea2, dark beast, "
+    "kreativity, nsfw, nude, portrait, face"
+)
+
+
 class _FakeCache:
     def __init__(self, items):
         self.raw_data = list(items)
@@ -147,6 +161,66 @@ def test_calculate_relative_path_sanitizes_double_slashes(isolated_settings):
     assert relative_path == "no tags/Author"
 
 
+def test_calculate_relative_path_ignores_keyword_dump_tag(isolated_settings):
+    """A tag holding a whole keyword list must not become a folder name (#1119)."""
+    model_data = {"base_model": "Krea 2", "tags": [KEYWORD_DUMP_TAG]}
+
+    relative_path = calculate_relative_path_for_model(model_data, "lora")
+
+    assert relative_path == "Krea 2/no tags"
+
+
+def test_calculate_relative_path_uses_next_usable_tag(isolated_settings):
+    """Unusable tags are skipped instead of hijacking the folder name (#1119)."""
+    model_data = {"base_model": "Krea 2", "tags": [KEYWORD_DUMP_TAG, "portrait"]}
+
+    assert calculate_relative_path_for_model(model_data, "lora") == "Krea 2/portrait"
+
+
+def test_calculate_relative_path_sanitizes_tag_segment(isolated_settings):
+    """A tag with path separators must not create nested folders."""
+    model_data = {"base_model": "SDXL", "tags": ["a/b:c"]}
+
+    assert calculate_relative_path_for_model(model_data, "lora") == "SDXL/a_b_c"
+
+
+def test_calculate_relative_path_caps_tag_segment(isolated_settings):
+    """A long configured priority tag is truncated to the tag length budget."""
+    long_tag = "y" * 80
+    isolated_settings["priority_tags"] = {"lora": long_tag}
+
+    model_data = {"base_model": "SDXL", "tags": [long_tag]}
+
+    relative_path = calculate_relative_path_for_model(model_data, "lora")
+
+    assert relative_path == "SDXL/" + "y" * MAX_PATH_TAG_LENGTH
+
+
+def test_calculate_relative_path_keeps_tag_within_budget(isolated_settings):
+    model_data = {"base_model": "SDXL", "tags": ["t" * 40]}
+
+    relative_path = calculate_relative_path_for_model(model_data, "lora")
+
+    assert relative_path == "SDXL/" + "t" * 40
+
+
+def test_calculate_relative_path_caps_model_and_version_names(isolated_settings):
+    isolated_settings["download_path_templates"]["lora"] = "{model_name}/{version_name}"
+
+    model_data = {
+        "model_name": "m" * 300,
+        "base_model": "SDXL",
+        "tags": [],
+        "civitai": {"id": 1, "name": "v" * 300, "creator": {"username": "Creator"}},
+    }
+
+    relative_path = calculate_relative_path_for_model(model_data, "lora")
+
+    assert relative_path == (
+        "m" * MAX_FOLDER_NAME_LENGTH + "/" + "v" * MAX_FOLDER_NAME_LENGTH
+    )
+
+
 def test_calculate_recipe_fingerprint_filters_and_sorts():
     loras = [
         {"hash": "ABC", "strength": 0.1234},
@@ -304,6 +378,32 @@ def test_calculate_filename_original_name_falls_back_to_file_name(isolated_setti
     assert calculate_filename_for_model(model_data, "lora") == "legacy-name-0123456789"
 
 
+def test_calculate_filename_drops_keyword_dump_tag(isolated_settings):
+    """The keyword-dump tag collapses instead of filling the filename (#1119)."""
+    _set_filename_templates(isolated_settings, "{base_model}-{first_tag}")
+
+    model_data = {
+        "base_model": "Krea 2",
+        "tags": [KEYWORD_DUMP_TAG],
+        "file_path": "/models/V1.safetensors",
+    }
+
+    assert calculate_filename_for_model(model_data, "lora") == "Krea 2"
+
+
+def test_calculate_filename_caps_rendered_stem(isolated_settings):
+    _set_filename_templates(isolated_settings, "{model_name}")
+
+    model_data = {
+        "model_name": "m" * 400,
+        "file_path": "/models/V1.safetensors",
+    }
+
+    result = calculate_filename_for_model(model_data, "lora")
+
+    assert len(result) == MAX_FILENAME_STEM_LENGTH
+
+
 @pytest.mark.parametrize(
     "original, expected",
     [
@@ -318,6 +418,27 @@ def test_sanitize_folder_name(original, expected):
     assert sanitize_folder_name(original) == expected
 
 
+def test_sanitize_folder_name_without_max_length_is_unbounded():
+    assert sanitize_folder_name("x" * 300) == "x" * 300
+
+
+@pytest.mark.parametrize(
+    "original, max_length, expected",
+    [
+        ("abcdefghij", 4, "abcd"),
+        # Re-trim separators and spaces exposed by the cut.
+        ("abc...defg", 4, "abc"),
+        ("abcdefg hij", 8, "abcdefg"),
+        # Shorter than the cap is returned untouched.
+        ("short", 10, "short"),
+        # A cut that leaves only separators falls back to "unnamed".
+        ("...abcdef", 3, "unnamed"),
+    ],
+)
+def test_sanitize_folder_name_truncates_to_max_length(original, max_length, expected):
+    assert sanitize_folder_name(original, max_length=max_length) == expected
+
+
 def test_get_lora_info_absolute_bare_name(mock_lora_scanner):
     mock_lora_scanner([
         {"file_name": "mylora", "folder": "SDXL", "file_path": "/models/Lora/SDXL/mylora.safetensors", "civitai": {"trainedWords": ["trigger1"]}},