Show workspace commits clearly in Changes (#2350)

* feat(commits): distinguish workspace history from base commits

Keep every workspace commit visible while bounding base history to ten
context commits, and make push and base state readable in the commit rail.

* fix(commits): preserve history when base refs disappear

Fall back to recent HEAD history for stale saved bases, and reject truncated
git output instead of presenting an incomplete commit list.

* fix(commits): classify history against the current base

Use the furthest-ahead local or remote base for classification, and re-infer
base history when saved worktree metadata points to a deleted branch.

packages/app/src/i18n/resources/ja.ts

@@ -806,7 +806,7 @@ export const ja: TranslationResources = {
         deletedFile: "削除済み",
         commits: {
           title: "コミット",
-          countLabel: "最近のコミット数: {{count}}",
+          countLabel: "ワークスペースのコミット数: {{count}}",
           fileDiffEmpty: "表示する変更はありません",
           fileDiffError: "ファイル差分の読み込みに失敗しました",
           loading: "コミットを読み込み中…",