psp: detect installed PS1 games (incl. Category Lite folders)

PS1 EBOOTs install as PSP/GAME/{category}/{GAME_ID}/EBOOT.PBP, which the
PSP index ignored (it only indexed ISO games/videos), so the app never
marked them 'on PSP'. Index homebrew EBOOTs by folder id + embedded title,
match PS1 library items against them, and make 'Delete from PSP' remove the
whole game folder.

app/psp.py

@@ -236,8 +236,11 @@ def list_installed(root):
 def build_index(inventory):
     """Build a lookup index for matching library discs against the PSP.
 
-    Returns ``{"raw": set, "names": set}`` where ``raw`` holds lowercase ISO
-    stems (exact filename match) and ``names`` holds fuzzy-normalized stems.
+    Returns ``{"raw", "names", "homebrew_ids", "homebrew_names"}`` where
+    ``raw`` holds lowercase ISO stems (exact filename match), ``names`` holds
+    fuzzy-normalized stems, and the homebrew keys index ``PSP/GAME/**/EBOOT.PBP``
+    (homebrew + PS1 Classics, including Category Lite subfolders) by folder id
+    and embedded title.
     """
     raw, names = set(), set()
     for group in ("games", "videos"):
@@ -247,7 +250,20 @@ def build_index(inventory):
             norm = matcher.normalize_name(stem)
             if norm:
                 names.add(norm)
-    return {"raw": raw, "names": names}
+
+    hb_ids, hb_names = set(), set()
+    for it in (inventory or {}).get("homebrew", []):
+        ident = str(it.get("id") or "").strip().lower()
+        if ident:
+            hb_ids.add(ident)
+        stem = Path(it.get("name") or "").stem.strip().lower()
+        if stem:
+            hb_names.add(stem)
+        norm = matcher.normalize_name(Path(it.get("name") or "").stem)
+        if norm:
+            hb_names.add(norm)
+    return {"raw": raw, "names": names,
+            "homebrew_ids": hb_ids, "homebrew_names": hb_names}
 
 
 def find_umd_iso(root):