Store library settings in the pool index and drop legacy sidecars

PROJECT.md

@@ -51,8 +51,9 @@ Curator manages a personal movie library based on two folders:
   loads the pool, and the GUI generates the Filmotéka tree via `HardlinkManager`.
 - `File` carries `title` + `csfd_link`. **Pool metadata lives in a unified index**
   (`<pool>/.Curator.!index`, see `pool_index.py`); `File` writes there when an
-  index is injected, and still falls back to per-file `.!tag` sidecars for
-  arbitrary (non-pool) folders.
+  index is injected. Without an index a `File` is an in-memory object only — the
+  old per-file `.!tag` sidecars and the per-folder `.!ftag` config have been
+  removed.
 
 ### GUI decision
 
@@ -65,6 +66,15 @@ movie table, and one-click Filmotéka generation.
 - **Metadata storage:** one **unified metadata file** for the whole pool (a
   central index), not per-file sidecars. Justified because Curator owns the pool
   and files are never moved manually, so it is not exposed to path drift.
+- **Config split by scope:** the global config (`.Curator.!gtag`) holds **app
+  data only** — window state, MRU folders, and the `pool_dir` / `filmoteka_dir`
+  pointers (which must stay global: the index is found *through* them). Everything
+  that describes a specific library — `tag_schema` and `copyasis_folders` — lives
+  in the pool index under a `settings` section, so it travels with the pool.
+  `FileManager` migrates any pre-existing global values into the index on first
+  open. The old per-folder `.!ftag` config and per-file `.!tag` sidecars were
+  removed (they were unused Tagger leftovers), and the orphaned tkinter
+  `src/ui/gui.py` went with them.
 - **Import dialog:** **multi-file** — pick several videos at once and give each
   its own **Title** + **ČSFD link** (one row per file, more can be added from the
   dialog), or auto-filled with **"Najít ČSFD odkazy"** (cleans each filename into