fix(release/parser): drop pure-punctuation TITLE tokens at assembly

Releases using ' - ' as a separator (Vinyl - 1x01 - FHD) tokenize to
['Vinyl', '-', '1x01', '-', 'FHD'] — the standalone '-' tokens were
ending up in title_parts and leaked into the joined title
('Vinyl.-'). We can't add '-' to the separator list (it would break
codec-GROUP), so we filter at assembly: a TITLE token with no
alphanumeric characters carries no title content.

Side win: same logic eliminates the UTF-8 wide-pipe '｜' from the
khruangbin_yt_wide_pipe fixture title.

Fixtures updated:
- shitty/vinyl_1x01_format/expected.yaml (title: Vinyl.- → Vinyl)
- path_of_pain/khruangbin_yt_wide_pipe/expected.yaml (｜ dropped)

tests/fixtures/releases/path_of_pain/khruangbin_yt_wide_pipe/expected.yaml

@@ -1,13 +1,15 @@
 release_name: "Khruangbin ｜ Austin City Limits Music Festival 2024 ｜ Full Set [V_-7WWPPeBs].webm"
 
 # yt-dlp slug: UTF-8 wide pipe '｜' (U+FF5C, not the ASCII '|'), trailing
-# YouTube video ID in brackets, .webm extension. Parser extracts the year
-# (2024) correctly but mistakes the YouTube ID '7WWPPeBs' for a release
-# group, and the wide pipe survives the tokenizer (not a separator).
+# YouTube video ID in brackets, .webm extension. The wide pipe survives
+# the tokenizer (not a separator) but is now dropped at title assembly
+# (pure-punctuation TITLE tokens carry no content). Year (2024) parses
+# correctly; the YouTube ID '7WWPPeBs' is still mistaken for a release
+# group (separate gap, see PoP backlog).
 # This is a concert recording — closer to "live music" than "movie", but
 # media_type=movie is the current degenerate best guess.
 parsed:
-  title: "Khruangbin.｜.Austin.City.Limits.Music.Festival"
+  title: "Khruangbin.Austin.City.Limits.Music.Festival"
   year: 2024
   season: null
   episode: null

tests/fixtures/releases/shitty/vinyl_1x01_format/expected.yaml

@@ -1,11 +1,12 @@
 release_name: "Vinyl - 1x01 - FHD"
 
-# Tech debt: surrounding ' - ' separators leave a stray '-' token attached
-# to the title ("Vinyl.-"). NxNN form correctly identifies S01E01; everything
-# tech-side empty (no quality token in KB — "FHD" not yet known). Anti-regression
-# the current degenerate title so a future fix is intentional.
+# Surrounding ' - ' separators in human-friendly release names left stray
+# '-' tokens attached to the title. They are now dropped at assembly time
+# (pure-punctuation TITLE tokens carry no content). NxNN form correctly
+# identifies S01E01; tech-side stays empty (no quality token in KB — "FHD"
+# not yet known).
 parsed:
-  title: "Vinyl.-"
+  title: "Vinyl"
   year: null
   season: 1
   episode: 1