fix(plex): the rails' Restart comes from the one rollup; plain text decodes whole entity names only

Both Continue-watching rails built a show's card state inline; they now take it from rollup.show_state, so a show part watched with nothing to resume offers Play alone there too. A named reference counts only when its whole name is an HTML5 entity: html.unescape still decoded the legacy "&not" inside "&notice;". Tests cover the grid's in-progress-but-not-resumable case through its SQL and both rails.

backend/app/plex/plaintext.py

@@ -9,6 +9,7 @@ that cleaned the existing rows calls it too, so the two cannot disagree.
 
 import html
 import re
+from html.entities import html5
 
 _BREAK = re.compile(r"<br\s*/?>", re.IGNORECASE)
 # A paragraph or block boundary: a blank line between the two. Only a tag name ends the match, so a
@@ -18,10 +19,17 @@ _TAG = re.compile(r"</?[a-zA-Z][^>]*>")
 _BLANKS = re.compile(r"[ \t]*\n[ \t]*\n\s*")
 
 # A well-formed character reference only. `html.unescape` alone also decodes the legacy forms that
-# have no semicolon, so prose like "AT&notice" or "R&copy" came out as "AT¬ice" and "R©".
+# have no semicolon, so prose like "AT&notice" or "R&copy" came out as "AT¬ice" and "R©". A named
+# one counts only when its whole name is an entity: for "&notice;" `html.unescape` still falls back
+# to the legacy "&not" inside it.
 _REF = re.compile(r"&(?:#[0-9]+|#[xX][0-9a-fA-F]+|[A-Za-z][A-Za-z0-9]*);")
 
 
+def _decode(m: re.Match[str]) -> str:
+    ref = m.group()
+    return html.unescape(ref) if ref[1] == "#" or ref[1:] in html5 else ref
+
+
 def plain_text(value: str | None) -> str | None:
     """`value` with its markup gone: line breaks kept as newlines, paragraphs as a blank line,
     every other tag dropped and entities decoded. None or an all-blank result stays None."""
@@ -31,6 +39,6 @@ def plain_text(value: str | None) -> str | None:
         value = _BREAK.sub("\n", value)
         value = _BLOCK.sub("\n\n", value)
         value = _TAG.sub("", value)
-        value = _REF.sub(lambda m: html.unescape(m.group()), value)
+        value = _REF.sub(_decode, value)
         value = _BLANKS.sub("\n\n", value)
     return value.strip() or None

backend/app/plex/rollup.py

@@ -107,7 +107,7 @@ def state_map(db: Session, user_id: int, show_ids: list[int]) -> dict[int, ShowS
 
 def item_state_map(db: Session, user_id: int, item_ids: list[int]) -> dict[int, PlexState]:
     """A user's PlexState rows for a set of leaf items (movies or episodes), keyed by item_id — the
-    leaf analogue of `state_map` (which rolls a show's episodes up to a status string). One batched
+    leaf analogue of `state_map` (which rolls a show's episodes up to a `ShowState`). One batched
     fetch, so the caller serializes cards without a per-card query. Empty in → empty dict (no `IN ()`)."""
     if not item_ids:
         return {}