Scene Manager: fixes from the first run against a real Libreflow

- Update / version switch: Blender 5.2 replaces the library on reload
  (renamed after its file, custom properties gone); find it by path and
  restore its name and tags.
- Remove the libraries an asset linked indirectly when it is removed or
  fails to load (remove_unused_libraries), never a managed one.
- Config: real Kitsu asset types for link modes and Shot Viewer groups,
  setdress_low files for bg_location, "environments" collection fallback.
- Dev fake server and test use the real asset types; rock links a node
  group from the essentials to cover the indirect library cleanup.
- README and CLAUDE.md updated with the live findings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

config.py

@@ -244,7 +244,14 @@ SHOT_VIEWER_RIG_GROUPS = {
     "Props": r"(?i)^(?:prp|prop)[_-]",
 }
 # Rigs loaded by the Scene Manager are grouped by their Libreflow asset type first.
-SHOT_VIEWER_ASSET_TYPE_GROUPS = {"chars": "Characters", "props": "Props"}
+SHOT_VIEWER_ASSET_TYPE_GROUPS = {
+    "main_character": "Characters",
+    "secondary_character": "Characters",
+    "tertiary_character": "Characters",
+    "main_props": "Props",
+    "secondary_props": "Props",
+    "vehicles": "Props",
+}
 
 # Shots added by the shot viewer. TODO: confirm with production.
 SHOT_NAME_FORMAT = "sh{:04d}"
@@ -271,13 +278,26 @@ LIBREFLOW_TIMEOUT = 15
 
 # Published file loaded for each asset type ("*" = the others): ordered
 # "task/file.ext" glob patterns, the first file of the asset matching one is loaded.
-SCENE_MANAGER_FILE_PATTERNS = {"*": ["rigging/*.blend", "modeling/*.blend"]}
+# TODO: confirm the set publishes (only setdress_low seen so far).
+SCENE_MANAGER_FILE_PATTERNS = {
+    "*": ["rigging/*.blend", "modeling/*.blend"],
+    "bg_location": ["setdress_low/*.blend"],
+}
 # Collection linked from an asset file: the first of these names found ({asset}
-# = asset name), else the file's single top-level collection.
-SCENE_MANAGER_COLLECTION_NAMES = ["COL_{asset}", "{asset}"]
-# How an asset type is brought in: "OVERRIDE" (library override, posable) or
-# "INSTANCE" (collection instance). "*" = the other types. TODO: confirm type names.
-SCENE_MANAGER_LINK_MODES = {"chars": "OVERRIDE", "props": "OVERRIDE", "*": "INSTANCE"}
+# = asset name), else the file's single top-level collection. "environments"
+# holds the set in the setdress files.
+SCENE_MANAGER_COLLECTION_NAMES = ["COL_{asset}", "{asset}", "environments"]
+# How an asset type (Kitsu name) is brought in: "OVERRIDE" (library override, posable)
+# or "INSTANCE" (collection instance). "*" = the other types. TODO: confirm with production.
+SCENE_MANAGER_LINK_MODES = {
+    "main_character": "OVERRIDE",
+    "secondary_character": "OVERRIDE",
+    "tertiary_character": "OVERRIDE",
+    "main_props": "OVERRIDE",
+    "secondary_props": "OVERRIDE",
+    "vehicles": "OVERRIDE",
+    "*": "INSTANCE",
+}
 # Collection gathering the loaded assets of a type, under the scene collection.
 SCENE_MANAGER_TYPE_COLLECTION = "COL_{asset_type}"
 # Default task of the assetize dialog.