refactor: Datei-Scope-Serialisierung entfernen

ScopeGlobs auf Tasks und SerializeOnFileOverlap auf der Listen-Config waren
ungenutzt: der Scope wurde nie befuellt, also hat der Queue-Picker nie
serialisiert. ScopeOverlap, das Picker-Gate, die DTO-Felder, die UI-Option und
die Spalten fallen weg (Migration DropFileScopeSerialization).

src/ClaudeDo.Localization/locales/en.json

@@ -391,8 +391,6 @@
       "manualListHint": "New tasks in this list start out manual: no queueing, running or refining, and automation skips them. You can still open a hand-driven session.",
       "findingsTracked": "Commit the .claudedo findings folder",
       "findingsTrackedHint": "Off: the folder stays out of git via .git/info/exclude. On: findings travel with the repo.",
-      "serializeOnFileOverlap": "Serialize tasks that touch the same files",
-      "serializeOnFileOverlapHint": "Off: tasks in this list run in parallel. On: a queued task whose declared file scope overlaps a running or awaiting-review sibling waits instead of starting.",
       "sectionAgent": "AGENT",
       "resetAgentSettings": "Reset agent settings",
       "sectionVerify": "VERIFICATION",