fix(release/parser): collapse chained multi-episode markers to full range

S14E09E10E11 previously parsed to episode=9, episode_end=10 — E11
was silently dropped. The parser now takes episodes[-1] as
episode_end so the full chain is captured (episode=9, episode_end=11).
Intermediate values stay implied.

Fixture shitty/archer_multi_episode/ updated from anti-regression of
the bug to anti-regression of the fix.

CHANGELOG.md

@@ -15,6 +15,15 @@ callers).
 
 ## [Unreleased]
 
+### Fixed
+
+- **Multi-episode chain (e.g. `S14E09E10E11`) now collapses to a full
+  range.** The parser previously captured `episode=9, episode_end=10`
+  and dropped E11+. It now returns `episode=first, episode_end=last`,
+  with intermediate values implied. Fixture
+  `shitty/archer_multi_episode/` updated from anti-regression-of-bug
+  to anti-regression-of-fix.
+
 ### Added
 
 - **`LanguageRepository` port** in `alfred.domain.shared.ports`. Structural

alfred/domain/release/parser/pipeline.py

@@ -113,7 +113,9 @@ def _parse_season_episode(text: str) -> tuple[int, int | None, int | None] | Non
 
         if not episodes:
             return None
-        return season, episodes[0], episodes[1] if len(episodes) >= 2 else None
+        # For chained multi-episode markers (E09E10E11), the range is the
+        # first → last episode. Intermediate values are implied.
+        return season, episodes[0], episodes[-1] if len(episodes) >= 2 else None
 
     # NxNN form
     if "X" in upper:

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

@@ -1,14 +1,13 @@
 release_name: "Archer.S14E09E10E11.1080p.WEB.h264-ETHEL"
 
-# Tech debt: triple-episode chain (E09E10E11) — current parser captures
-# episode=9 and episode_end=10, but E11 is lost. Anti-regression: lock in
-# the partial behavior so any future improvement is intentional.
+# Triple-episode chain (E09E10E11) — the parser collapses the chain to a
+# range (episode=first, episode_end=last). Intermediate values are implied.
 parsed:
   title: "Archer"
   year: null
   season: 14
   episode: 9
-  episode_end: 10
+  episode_end: 11
   quality: "1080p"
   source: "WEB"
   codec: "h264"