refactor: delete unreachable members and redundant package refs

Eight public members had no caller anywhere in src: GitService.GetFileDiffAsync,
SubtaskRepository.DeleteByTaskIdAsync, TaskRepository.GetByListAsync (a
backwards-compat alias for GetByListIdAsync) and .GetByCreatorAsync,
WorktreeRepository.GetByStatesAsync, TaskMonitorViewModel.SetPendingQuestion
(a duplicate of the live-event lambda), PrimeClaudeTabViewModel.ApplyFiredEvent,
and StreamLineFormatter.FormatFile. TaskAttachmentRepository.DeleteAllForTaskAsync
was reachable only from its own test; the ON DELETE CASCADE on task_attachments
already covers it. Tests for the deleted members go with them.

Dropped two package refs the platform already provides: EntityFrameworkCore.Design
in Worker (the design-time factory and the migrations live in Data, which has its
own ref) and System.IO.FileSystem.AccessControl in Installer.Tests (net8.0-windows
ships the ACL APIs in the shared framework).

src/ClaudeDo.Data/CLAUDE.md

@@ -53,7 +53,7 @@ Worker's `QueuePicker` (`FromSqlRaw`), **not** here.
 - **TaskRepository** — CRUD, planning helpers (`CreateChildAsync`, `SetPlanningStartedAsync`, `DiscardPlanningAsync`, `UpdateChildAsync`), `UpdateAgentSettingsAsync`. ⚠️ Status-mutation primitives (`MarkRunningAsync`/`MarkDoneAsync`/`MarkFailedAsync`/`FlipAllRunningToFailedAsync`) are **`internal`** — only the Worker's `TaskStateService` may call them. `CreateChildAsync` produces children with `Status=Idle, PlanningPhase=None`. **Task-number allocation:** `AddAsync` (line 20) and `CreateChildAsync` (line 276) are the two sole task-creation paths; both call `TaskNumberAllocator.AddWithNumberAsync` to allocate a number atomically during the same transaction as the insert. Every other creation path (UI, MCP `add_task`, `batch_add_tasks`, Online Inbox sync, merge-helper handler tasks, planning children) routes through one of these two.
 - **ListRepository** — CRUD, `GetConfigAsync`/`SetConfigAsync` (upsert)/`DeleteConfigAsync` for `list_config`
 - **WorktreeRepository** — CRUD, `UpdateHeadAsync`, `SetStateAsync`, `SetMergedAsync` (atomically sets State=Merged **and** stamps MergeCommit in one update — the only writer of MergeCommit)
-- **TaskAttachmentRepository** — `AddAsync`, `UpdateAsync`, `GetAsync(taskId, fileName)`, `ListByTaskIdAsync`, `DeleteAsync(taskId, fileName)`, `DeleteAllForTaskAsync`
+- **TaskAttachmentRepository** — `AddAsync`, `UpdateAsync`, `GetAsync(taskId, fileName)`, `ListByTaskIdAsync`, `DeleteAsync(taskId, fileName)`. Bulk delete-per-task is the `ON DELETE CASCADE` on `task_attachments`, not a repository method.
 - **DailyNoteRepository**, **WeekReportRepository**, **TaskRunRepository**, **SubtaskRepository**, **AppSettingsRepository**
 
 `TaskRepository.DeleteAsync` and `ListRepository.DeleteAsync` also delete the on-disk attachment
@@ -74,7 +74,7 @@ dir(s) via an optional `AttachmentStore` ctor param (defaults to the production
 - Worktrees: add (**serialized** to avoid a commondir race), remove, prune, list paths for branch
 - Branches: current, list local, checkout, delete
 - Staging/commit: status porcelain, add-all, add-path, commit via stdin
-- Diffs: working tree, branch vs base, commit range `base..head` (shows a merged task's diff after the worktree is gone), per-file, diff-stat, committed files, has-changes
+- Diffs: working tree, branch vs base, commit range `base..head` (shows a merged task's diff after the worktree is gone), diff-stat, committed files, has-changes
 - Merge: ff-only, no-ff, abort, mid-merge detection (`MERGE_HEAD`), conflicted files
 - Revert: `RevertMergeCommitAsync` (`git revert --no-edit -m 1 <sha>`), `RevertAbortAsync`, `IsMidRevertAsync` (`REVERT_HEAD`, mirrors `IsMidMergeAsync`)
 - `PreviewMergeAsync` (non-destructive check via `git merge-tree --write-tree`), `CountChangedFilesAsync`, rev-parse, is-git-repo