docs(unification): spec + phased plan for one-component-per-feature

Maps duplication into three buckets (parallel impls, entry-point sprawl, dead/leftover) and defines six phased unification slices: groundwork, DialogService, MergeCoordinator, WorktreeActions, AgentConfigeditor, unified DiffViewer.

docs/superpowers/plans/2026-06-19-feature-unification-plan.md

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+# Feature unification — phased plan
+
+Date: 2026-06-19
+Design: `docs/superpowers/specs/2026-06-19-feature-unification-design.md`
+
+Six slices, sequenced cheapest/lowest-risk first. Each ends green
+(`dotnet build -c Release` + the touched test project) and is independently
+committable. Phases 0–1 are detailed here; 2–5 are scoped, and each gets its own
+`docs/superpowers/plans/2026-06-19-unify-<slice>.md` when picked up (per the
+2026-06-05 layer-A/B/C convention). Build per-csproj (`-c Release`) — `.slnx` needs
+.NET 9 and a running Worker locks `Debug`.
+
+---
+
+## Phase 0 — Groundwork (Bucket C). No UX change.
+
+**0a. Delete the dead hunks conflict API (C1).**
+- Remove `TaskMergeService.GetConflictsAsync` + the `MergeConflicts`/`ConflictFileContent` records it returns (`src/ClaudeDo.Worker/Lifecycle/TaskMergeService.cs:250`) if unused elsewhere.
+- Remove `WorkerHub.GetMergeConflicts` (`src/ClaudeDo.Worker/Hub/WorkerHub.cs:378`) + `MergeConflictsDto`/`ConflictFileDto`/`ConflictHunkDto` if unused.
+- Remove `WorkerClient`'s `"GetMergeConflicts"` invoke (`src/ClaudeDo.Ui/Services/WorkerClient.cs:276`) + the `IWorkerClient` member + every fake override (`tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs`, `TasksIslandViewModelPlanningTests.cs`, others — grep `GetMergeConflicts`).
+- Delete `TaskMergeServiceTests.cs:672` `GetConflictsAsync_AfterConflictMerge_ReturnsOursAndTheirs`.
+- Verify with grep first: `GetConflictsAsync` and `GetMergeConflicts` have **no** callers outside this chain + tests.
+- Acceptance: Worker + Ui build; Worker.Tests + Ui.Tests green; `GetMergeConflictDocuments` path untouched.
+
+**0b. Single task-creation path (C2).**
+- Identify the path MCP `ExternalMcpService.AddTask` uses; expose a thin creation method (repository or a small `TaskCreationService`) that applies the same defaults (ListId, SortOrder, CreatedAt).
+- Re-point `TasksIslandViewModel.AddAsync` at it instead of `db.Tasks.Add` direct EF.
+- Acceptance: quick-add still works; one creation path; Ui.Tests + Worker.Tests green.
+
+**0c. Prune stale worktrees (C3).**
+- `git worktree list`; remove the orphaned `.claude/worktrees/*` entries (confirm each is unwanted with Mika before `git worktree remove`).
+- Acceptance: only intended worktrees remain; no tracked files change.
+
+> C4 (naming alignment) intentionally NOT in this phase — see design.
+
+---
+
+## Phase 1 — DialogService (B3–B5). Low–medium.
+
+**Goal:** one `IDialogService` replaces the scattered `Show*` Func seams and the
+duplicate open-commands.
+
+- New `IDialogService` (Ui/Services) with typed methods: `OpenListSettings(ListNavItemViewModel)`, `OpenRepoImport()`, `OpenWorktreesOverview(string? listId)`, `OpenWeeklyReport()`, `OpenAbout()`, `OpenWorkerConnectionHelp()`. Implementation owns the factories + `ModalShell`/TCS wiring currently in `MainWindow.axaml.cs` + `IslandsShellViewModel.cs:59-71`.
+- Inject it into `ListsIslandViewModel`, `TasksIslandViewModel`, `IslandsShellViewModel`. Collapse the three List-Settings doors (Lists context menu, Tasks header, shell bridge `IslandsShellViewModel.cs:190-194`) to one `dialogs.OpenListSettings(row)` call; same for Repo Import (2→1) and Worktrees Overview (2→1, keep the `listId?` param for global-vs-per-list).
+- Keep `ModalShell`/TCS dialog pattern; this only centralizes *opening*.
+- Update fakes/ctors per the IWorkerClient-fakes hazard (ctor changes ripple to Ui.Tests).
+- Acceptance: every dialog opens via one method; no duplicate open-commands; Ui.Tests green; visual gap flagged (open each dialog from each former door).
+
+---
+
+## Phase 2 — MergeCoordinator (B1). Medium.
+
+**Goal:** delete the five `RequestConflictResolution` seams; one coordinator.
+
+- New `IMergeCoordinator` (Ui) `MergeAsync(taskId, targetBranch)` = the body of `IslandsShellViewModel.RequestConflictResolutionAsync` (`:49`) plus the "open MergeModal → on conflict open resolver" flow currently split across `MergeModalViewModel:108` and `DiffModalViewModel:103`.
+- Remove the `Func<string,string,Task>? RequestConflictResolution` from `WorktreesOverviewModalViewModel:83`, `DiffModalViewModel:75`, `MergeModalViewModel:33`, `MergeSectionViewModel:51`, and the `DetailsIslandViewModel:347` delegate; inject the coordinator instead.
+- Re-point doors: review Approve, Diff Merge button, WorktreesOverview single + batch (`:331`), Details merge section.
+- Update seam tests (`WorktreesOverviewBatchMergeTests.cs:145`, `DetailsIslandConflictSeamTests.cs:84`) to assert via the coordinator.
+- Acceptance: one merge entry API; resolver still opens for single-task AND planning conflict; Ui.Tests green; visual gap flagged (force a conflict from Approve and from the Diff Merge button).
+
+---
+
+## Phase 3 — WorktreeActions (A3). Medium.
+
+**Goal:** one per-task worktree-actions VM reused by overview rows + Details.
+
+- New `WorktreeActionsViewModel(taskId)` with Merge/Diff/Discard/Keep/ForceRemove over `IWorkerClient` (uses the Phase-2 coordinator for Merge, the Phase-5 viewer for Diff — until then, current calls).
+- `WorktreesOverviewModalViewModel` rows compose one each; `MergeSectionViewModel` hosts one for the active task. Remove the duplicated commands.
+- Acceptance: both surfaces drive the same VM; Ui.Tests green; visual gap flagged.
+
+---
+
+## Phase 4 — AgentConfigEditor (A2). Medium.
+
+**Goal:** one config editor for Global | List | Task scope.
+
+- New `AgentConfigEditorViewModel(scope)` over `InheritanceResolver` exposing Model/SystemPrompt/AgentPath/MaxTurns + reset commands + `InheritedBadge` state; persists via the scope's hub method (`UpdateListConfig` / `UpdateTaskAgentSettings` / app settings).
+- Embed in `SettingsModalViewModel`, `ListSettingsModalViewModel`, and the Details `AgentSettingsSectionViewModel` host; delete the duplicated field/reset logic.
+- Acceptance: identical editor in all three scopes; Localization parity; Ui.Tests green; visual gap flagged.
+
+---
+
+## Phase 5 — DiffViewer (A1 + B2). High; last.
+
+**Goal:** one diff component replaces DiffModal + WorktreeModal + PlanningDiff.
+
+- New `DiffViewerViewModel` with `DiffSource` enum/abstraction (`DirtyWorktree | BranchVsBase | CommitRange | PlanningAggregate | IntegrationBranch`) and an optional file-tree pane (port `WorktreeModal`'s tree + Avalonia-12 selection workaround); reuse `UnifiedDiffParser` + `DiffLinesView`; keep PlanningDiff's combined-mode toggle as a source switch.
+- Re-point all B2 doors to open it with the right source. Remove the three old VMs/views.
+- Update `DiffModalViewModelTests`, `PlanningDiffViewModelTests`.
+- Acceptance: every diff door opens the one viewer; whole-unified AND file-tree layouts work; Ui.Tests green; visual gap flagged (worktree-dirty, post-merge commit-range, planning per-subtask + integration).
+
+---
+
+## Sequencing rationale
+
+0 (delete/no-UX) → 1 (isolated, unblocks nothing but cheap) → 2 (coordinator; 3 & 5
+lean on it for Merge/Diff) → 3 → 4 (independent) → 5 (biggest, most UX-sensitive,
+benefits from 2's coordinator). Stop after any phase and the app is shippable.
+
+## Per-phase commits
+
+Conventional Commits, one per phase (or per sub-step in Phase 0): e.g.
+`refactor(merge): single MergeCoordinator replaces 5 conflict seams`. Stage by path
+(never `git add -A` — concurrent sessions). Commit the spec + this plan first.