ComfyUI hands its model folders over in the host's own spelling --
`utils/extra_config.py` runs every configured path through `os.path.normpath()`,
which is all backslashes on Windows, and `main.py` registers `<output>/loras`
unconditionally for its save nodes. `Config` kept that spelling verbatim while
`_prepare_*_paths()` normalized the live root lists to forward slashes, and the
scanner compared the two as raw strings. On Windows every configured root
therefore looked like a root that was not in the live list: the Refresh menu
listed each directory twice (the twin showing "0 models"), the completion toast
claimed reachable roots were "currently inaccessible" and kept their whole cache
count as `kept_unreachable`, and the settings sync persisted host-registered
directories that were never created.
The duplication was not only cosmetic. `_UnreachablePaths.add()` normalizes the
prefix it is given, so the configured twin of a live root registered exactly the
live root's prefix as unreadable: in the prune phase every cached-but-missing
entry under it matched and was "kept", so models deleted from disk were never
removed from the cache again.
* `py/utils/root_paths.py` holds the single `normalize_root_identity()`
(separator style, redundant/trailing separators, and case where the filesystem
folds it: whole paths on Windows, drive letters everywhere). `config.py` and
`settings_manager.py` each carried a private copy and `model_scanner.py`
compared raw strings.
* `ModelScanner` compares root identities in `get_configured_model_roots()`,
`describe_model_roots()` (dedupe + `available`), the reconcile's
`configured_only` list and the `ReconcileScope.roots` membership test, so one
directory is one root whatever the host called it. `_normalized_root_prefix()`
is built on the same identity, and an empty prefix no longer matches every
path.
* A configured root that never made it into the live list is reported only while
it still holds cached entries -- in the menu and in `skipped_roots` /
`unavailable_paths` alike. A directory that neither exists nor was ever scanned
has nothing to keep, so `<output>/loras` stops being an unavailable root.
* The startup sync drops saved roots that neither exist nor hold cached entries
(`PersistentModelCache.roots_with_cached_entries()`, one scan per model type,
separator-agnostic and wildcard-escaped). A root named by the library's
`default_*_root` is kept even when empty: dropping it would let the next boot
"repair" the default onto another root. When the cache cannot be consulted,
every root is kept.
* `GET /scan?roots=` validates requested roots by identity too, so the browser
extension or a script passing the spelling settings.json holds selects the root
instead of answering 400 "Unknown model root(s)".
Verified: 8 of the new tests fail against the pre-fix source (checked with the
fix stashed); 3798 passed, 7 skipped, 11 deselected. The probe costs 71ms for a
100k-model library with seven missing roots (357ms when probing root by root).
