# M5 — Tasks Port Implementation Plan > **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking. **Goal:** Add a `tasks.Provider` port with an Amazing Marvin adapter (`am --json`) that lists today's open tasks; surface them on the planning screen as clickable chips that seed the intent field. **Architecture:** A new leaf package `internal/tasks` (interface + primitives only, like `ai`) with a CLI adapter that shells out to ampy's `am --json`. The `session.Controller` fetches the list asynchronously on entering planning — mirroring the existing planning coach (generation counter, status enum, graceful degradation) — and projects it into the broadcast `State`. The browser renders the list during planning; clicking a task fills `#intent`, which flows into the unchanged coach pipeline. Read-only; no writeback; no new endpoints. **Tech Stack:** Go 1.26, stdlib `os/exec` + `encoding/json`, Gin + SSE (unchanged), vanilla JS/CSS, stdlib `testing`. **Reference:** Design spec at `docs/superpowers/specs/2026-05-31-m5-tasks-port-design.md`. The patterns being mirrored: the `ai` port (`internal/ai/coach.go`, `internal/ai/backend.go`) and the planning coach in `internal/session/session.go` (`RequestCoach`, `resetCoachLocked`, `CoachView`). --- ## File Structure - **Create `internal/tasks/tasks.go`** — the `Provider` interface and the `Task` value type. Leaf package; imports only `context`. - **Create `internal/tasks/marvin.go`** — the `Marvin` adapter (shells out to `am --json`), an injectable `runner`, and the pure `parse` function. - **Create `internal/tasks/marvin_test.go`** — `parse` table tests, command-splitting test, and adapter tests with a fake runner. - **Modify `internal/session/session.go`** — add tasks fields, `TaskView`/`TasksView`, `State.Tasks`, `SetTasks`, `startTasksFetchLocked`, the planning-only projection, and the `EnterPlanning` hook. - **Modify `internal/session/session_test.go`** — `fakeProvider`, `waitTasksStatus`, and four controller tests. - **Modify `cmd/antidriftd/main.go`** — construct the Marvin adapter and call `ctrl.SetTasks`. - **Modify `internal/web/web_test.go`** — `stubProvider` and a planning-payload-carries-tasks test. - **Modify `internal/web/static/app.js`** — `updatePlanningTasks`, a tasks band in the planning render, and calls from both render paths. - **Modify `internal/web/static/app.css`** — `.tasklist` / `.task-chip` styling. --- ## Task 1: `tasks` package (port + Marvin adapter) **Files:** - Create: `internal/tasks/tasks.go` - Create: `internal/tasks/marvin.go` - Test: `internal/tasks/marvin_test.go` - [ ] **Step 1: Write the port interface and value type** Create `internal/tasks/tasks.go`: ```go // Package tasks is the Tasks port: it answers "what should I be doing?" by // listing the open to-do items due today or earlier. It imports nothing from // the rest of the app, so it stays a leaf package. package tasks import "context" // Task is one to-do item. Primitives only, so tasks stays a leaf package. type Task struct { ID string Title string Day string // "YYYY-MM-DD", or "" if unscheduled } // Provider answers "what should I be doing?" — the open tasks due today or // earlier. type Provider interface { Today(ctx context.Context) ([]Task, error) } ``` - [ ] **Step 2: Write the failing adapter tests** Create `internal/tasks/marvin_test.go`: ```go package tasks import ( "context" "errors" "testing" ) func TestParse(t *testing.T) { cases := []struct { name string in string want []Task wantErr bool }{ { name: "valid array", in: `[{"id":"a","title":"Write spec","parentId":"p","day":"2026-05-31","done":false}]`, want: []Task{{ID: "a", Title: "Write spec", Day: "2026-05-31"}}, }, {name: "empty array", in: `[]`, want: []Task{}}, {name: "json null", in: `null`, want: []Task{}}, { name: "drops done and empty-title", in: `[{"id":"a","title":"keep","day":"","done":false},{"id":"b","title":"done one","done":true},{"id":"c","title":" ","done":false}]`, want: []Task{{ID: "a", Title: "keep", Day: ""}}, }, {name: "malformed", in: `not json`, wantErr: true}, } for _, tc := range cases { t.Run(tc.name, func(t *testing.T) { got, err := parse([]byte(tc.in)) if tc.wantErr { if err == nil { t.Fatal("want error, got nil") } return } if err != nil { t.Fatalf("parse: %v", err) } if len(got) != len(tc.want) { t.Fatalf("len = %d, want %d (%+v)", len(got), len(tc.want), got) } for i := range got { if got[i] != tc.want[i] { t.Errorf("[%d] = %+v, want %+v", i, got[i], tc.want[i]) } } }) } } func TestNewMarvinCommandSplitting(t *testing.T) { cases := []struct { in string wantCmd string wantArgs []string }{ {"", "am", []string{"--json"}}, {"am", "am", []string{"--json"}}, {"uv run am", "uv", []string{"run", "am", "--json"}}, } for _, tc := range cases { m := NewMarvin(tc.in) if m.cmd != tc.wantCmd { t.Errorf("NewMarvin(%q).cmd = %q, want %q", tc.in, m.cmd, tc.wantCmd) } if len(m.args) != len(tc.wantArgs) { t.Fatalf("NewMarvin(%q).args = %v, want %v", tc.in, m.args, tc.wantArgs) } for i := range m.args { if m.args[i] != tc.wantArgs[i] { t.Errorf("NewMarvin(%q).args[%d] = %q, want %q", tc.in, i, m.args[i], tc.wantArgs[i]) } } } } func TestTodayUsesRunnerOutput(t *testing.T) { m := NewMarvin("am") var gotName string var gotArgs []string m.run = func(ctx context.Context, name string, args ...string) ([]byte, error) { gotName, gotArgs = name, args return []byte(`[{"id":"x","title":"Do thing","day":"2026-05-31","done":false}]`), nil } got, err := m.Today(context.Background()) if err != nil { t.Fatalf("Today: %v", err) } if gotName != "am" || len(gotArgs) != 1 || gotArgs[0] != "--json" { t.Fatalf("runner called with %q %v", gotName, gotArgs) } if len(got) != 1 || got[0].Title != "Do thing" { t.Fatalf("Today result = %+v", got) } } func TestTodayPropagatesError(t *testing.T) { m := NewMarvin("am") m.run = func(ctx context.Context, name string, args ...string) ([]byte, error) { return nil, errors.New("am not found") } if _, err := m.Today(context.Background()); err == nil { t.Fatal("want error from failing runner") } } ``` - [ ] **Step 3: Run the tests to verify they fail** Run: `go test ./internal/tasks/ -v` Expected: FAIL — `undefined: NewMarvin`, `undefined: parse` (build error). - [ ] **Step 4: Write the adapter implementation** Create `internal/tasks/marvin.go`: ```go package tasks import ( "bytes" "context" "encoding/json" "fmt" "os/exec" "strings" ) // runner executes a command and returns its stdout. Production shells out; // tests inject a fake to avoid spawning a process. type runner func(ctx context.Context, name string, args ...string) ([]byte, error) func execRunner(ctx context.Context, name string, args ...string) ([]byte, error) { cmd := exec.CommandContext(ctx, name, args...) var out, errb bytes.Buffer cmd.Stdout = &out cmd.Stderr = &errb if err := cmd.Run(); err != nil { if s := strings.TrimSpace(errb.String()); s != "" { return nil, fmt.Errorf("%s: %w: %s", name, err, s) } return nil, fmt.Errorf("%s: %w", name, err) } return out.Bytes(), nil } // Marvin is the Amazing Marvin adapter. It shells out to ampy's CLI // (`am --json`, no subcommand) and parses the open tasks due today or earlier. type Marvin struct { cmd string args []string run runner } // NewMarvin builds the adapter. command is split on spaces so both "am" and // "uv run am" work; empty defaults to "am". The "--json" flag is always // appended, and no subcommand is passed (ampy lists today's tasks by default). func NewMarvin(command string) *Marvin { fields := strings.Fields(command) if len(fields) == 0 { fields = []string{"am"} } args := append([]string{}, fields[1:]...) args = append(args, "--json") return &Marvin{cmd: fields[0], args: args, run: execRunner} } // Today returns the open tasks due today or earlier, or an error if the CLI // fails. Callers degrade gracefully on error. func (m *Marvin) Today(ctx context.Context) ([]Task, error) { out, err := m.run(ctx, m.cmd, m.args...) if err != nil { return nil, err } return parse(out) } type rawTask struct { ID string `json:"id"` Title string `json:"title"` Day string `json:"day"` Done bool `json:"done"` } // parse maps `am --json` output (a JSON array of task objects) to []Task. It // drops tasks that are done or have an empty title. A JSON null or empty array // yields an empty slice, not an error. func parse(data []byte) ([]Task, error) { var raw []rawTask if err := json.Unmarshal(data, &raw); err != nil { return nil, fmt.Errorf("tasks: parse: %w", err) } out := make([]Task, 0, len(raw)) for _, r := range raw { title := strings.TrimSpace(r.Title) if r.Done || title == "" { continue } out = append(out, Task{ID: r.ID, Title: title, Day: r.Day}) } return out, nil } ``` - [ ] **Step 5: Run the tests to verify they pass** Run: `go test ./internal/tasks/ -v` Expected: PASS — `TestParse`, `TestNewMarvinCommandSplitting`, `TestTodayUsesRunnerOutput`, `TestTodayPropagatesError`. - [ ] **Step 6: Commit** ```bash git add internal/tasks/tasks.go internal/tasks/marvin.go internal/tasks/marvin_test.go git commit -m "$(cat <<'EOF' Add tasks port and Amazing Marvin adapter The tasks.Provider port answers "what should I be doing?". The Marvin adapter shells out to ampy's `am --json` and parses today's open tasks, dropping done/empty-title entries. Leaf package mirroring ai. Co-Authored-By: Claude Opus 4.8 EOF )" ``` --- ## Task 2: Controller wiring (async fetch + projection) **Files:** - Modify: `internal/session/session.go` - Test: `internal/session/session_test.go` - [ ] **Step 1: Write the failing controller tests** Append to `internal/session/session_test.go`. Add `"antidrift/internal/tasks"` to the import block first, then add: ```go type fakeProvider struct { list []tasks.Task err error gate chan struct{} // if non-nil, Today blocks until it receives } func (f *fakeProvider) Today(ctx context.Context) ([]tasks.Task, error) { if f.gate != nil { <-f.gate } return f.list, f.err } // waitTasksStatus polls until the tasks view reaches want, or fails after 2s. func waitTasksStatus(t *testing.T, c *Controller, want string) State { t.Helper() deadline := time.Now().Add(2 * time.Second) for time.Now().Before(deadline) { st := c.State() if st.Tasks != nil && st.Tasks.Status == want { return st } time.Sleep(5 * time.Millisecond) } t.Fatalf("tasks status never reached %q (last: %+v)", want, c.State().Tasks) return State{} } func TestEnterPlanningFetchesTasks(t *testing.T) { c, _ := newTestController(t) c.SetTasks(&fakeProvider{list: []tasks.Task{{ID: "a", Title: "Write spec", Day: "2026-05-31"}}}) if err := c.EnterPlanning(); err != nil { t.Fatalf("enter planning: %v", err) } st := waitTasksStatus(t, c, "ready") if len(st.Tasks.Tasks) != 1 || st.Tasks.Tasks[0].Title != "Write spec" { t.Fatalf("tasks list wrong: %+v", st.Tasks) } } func TestTasksFetchError(t *testing.T) { c, _ := newTestController(t) c.SetTasks(&fakeProvider{err: errors.New("am down")}) if err := c.EnterPlanning(); err != nil { t.Fatalf("enter planning: %v", err) } st := waitTasksStatus(t, c, "error") if len(st.Tasks.Tasks) != 0 { t.Fatalf("error state should carry no tasks: %+v", st.Tasks) } } func TestNoProviderNoTasksView(t *testing.T) { c, _ := newTestController(t) if err := c.EnterPlanning(); err != nil { t.Fatalf("enter planning: %v", err) } if c.State().Tasks != nil { t.Fatalf("nil provider should yield no tasks view: %+v", c.State().Tasks) } } func TestTasksViewAbsentOutsidePlanning(t *testing.T) { c, _ := newTestController(t) c.SetTasks(&fakeProvider{list: []tasks.Task{{ID: "a", Title: "x"}}}) if c.State().Tasks != nil { t.Fatalf("no tasks view while Locked: %+v", c.State().Tasks) } } ``` - [ ] **Step 2: Run the tests to verify they fail** Run: `go test ./internal/session/ -run 'Tasks|FetchesTasks' -v` Expected: FAIL — `c.SetTasks undefined` and `st.Tasks undefined` (build error). - [ ] **Step 3: Add the import and constants** In `internal/session/session.go`, add `"antidrift/internal/tasks"` to the import block (it already imports `"antidrift/internal/ai"`). Immediately after the existing coach constants block (the `const ( coachIdle = "idle" … )` group near the top of the file), add: ```go const tasksTimeout = 30 * time.Second const ( tasksIdle = "idle" tasksPending = "pending" tasksReady = "ready" tasksError = "error" ) ``` - [ ] **Step 4: Add the controller fields** In the `Controller` struct, immediately after the coach fields (`coachGen int`), add: ```go tasksProvider tasks.Provider tasksStatus string tasksList []tasks.Task tasksGen int ``` (Field is named `tasksProvider`, not `tasks`, so it does not shadow the `tasks` package.) - [ ] **Step 5: Add the view types** Immediately after the `CoachView` struct definition, add: ```go // TaskView is one to-do item in the planning tasks list. type TaskView struct { ID string `json:"id"` Title string `json:"title"` Day string `json:"day,omitempty"` } // TasksView projects the ephemeral planning tasks state (Marvin's today list). type TasksView struct { Status string `json:"status"` Tasks []TaskView `json:"tasks,omitempty"` } ``` In the `State` struct, add a field immediately after `Coach *CoachView … `: ```go Tasks *TasksView `json:"tasks,omitempty"` ``` - [ ] **Step 6: Add the planning-only projection** In `stateLocked`, inside the existing `if c.runtimeState == domain.RuntimePlanning {` block, immediately after `st.Coach = cv`, add: ```go if c.tasksProvider != nil { tstatus := c.tasksStatus if tstatus == "" { tstatus = tasksIdle } tv := &TasksView{Status: tstatus} for _, t := range c.tasksList { tv.Tasks = append(tv.Tasks, TaskView{ID: t.ID, Title: t.Title, Day: t.Day}) } st.Tasks = tv } ``` - [ ] **Step 7: Add SetTasks and the async fetch** Immediately after `resetCoachLocked` (so the tasks helpers sit next to the coach helpers), add: ```go // SetTasks injects the Tasks provider. Mirrors SetCoach. A nil provider keeps // the planning tasks list absent. func (c *Controller) SetTasks(p tasks.Provider) { c.mu.Lock() c.tasksProvider = p c.mu.Unlock() } // startTasksFetchLocked kicks off an asynchronous Today() fetch when a provider // is set. Mirrors RequestCoach: generation-guarded, discards stale or // post-planning results, and notifies on completion. Caller holds mu. func (c *Controller) startTasksFetchLocked() { c.tasksList = nil if c.tasksProvider == nil { c.tasksStatus = tasksIdle return } c.tasksGen++ gen := c.tasksGen c.tasksStatus = tasksPending provider := c.tasksProvider go func() { ctx, cancel := context.WithTimeout(context.Background(), tasksTimeout) defer cancel() list, err := provider.Today(ctx) c.mu.Lock() if gen != c.tasksGen || c.runtimeState != domain.RuntimePlanning { c.mu.Unlock() return // stale or left planning: discard } if err != nil { c.tasksStatus = tasksError c.tasksList = nil } else { c.tasksStatus = tasksReady c.tasksList = list } c.mu.Unlock() c.notify() }() } ``` (`context` is already imported in `session.go`.) - [ ] **Step 8: Hook the fetch into EnterPlanning** In `EnterPlanning`, add `c.startTasksFetchLocked()` immediately after the existing `c.resetCoachLocked()` line: ```go c.runtimeState = next c.resetCoachLocked() c.startTasksFetchLocked() return c.persistLocked() ``` (Launching the goroutine while holding `mu` is safe: its first action is the `Today()` call, so it only blocks on the lock after `EnterPlanning` has returned and released it.) - [ ] **Step 9: Run the tests to verify they pass** Run: `go test ./internal/session/ -run 'Tasks|FetchesTasks' -v` Expected: PASS — `TestEnterPlanningFetchesTasks`, `TestTasksFetchError`, `TestNoProviderNoTasksView`, `TestTasksViewAbsentOutsidePlanning`. - [ ] **Step 10: Run the full session suite (no regressions, race-clean)** Run: `go test -race ./internal/session/` Expected: PASS (existing coach/drift/nudge tests unaffected — `EnterPlanning` with no provider just sets the idle status). - [ ] **Step 11: Commit** ```bash git add internal/session/session.go internal/session/session_test.go git commit -m "$(cat <<'EOF' Fetch today's tasks asynchronously on entering planning The controller fetches the Marvin task list when entering planning, mirroring the planning coach: generation-guarded goroutine, status enum (idle/pending/ready/error), projected into State only while planning and only when a provider is set. nil provider degrades to no tasks view. Co-Authored-By: Claude Opus 4.8 EOF )" ``` --- ## Task 3: Daemon wiring + web payload test **Files:** - Modify: `cmd/antidriftd/main.go` - Test: `internal/web/web_test.go` - [ ] **Step 1: Write the failing web test** Append to `internal/web/web_test.go`. Add `"antidrift/internal/tasks"` to the import block first, then add: ```go type stubProvider struct { list []tasks.Task } func (s stubProvider) Today(ctx context.Context) ([]tasks.Task, error) { return s.list, nil } func TestPlanningStatePayloadCarriesTasks(t *testing.T) { s := newTestServer(t) s.ctrl.SetTasks(stubProvider{list: []tasks.Task{{ID: "a", Title: "Write the spec", Day: "2026-05-31"}}}) r := s.Router() if w := post(t, r, "/planning", ""); w.Code != http.StatusOK { t.Fatalf("/planning code %d", w.Code) } deadline := time.Now().Add(2 * time.Second) for time.Now().Before(deadline) { if tv := s.ctrl.State().Tasks; tv != nil && tv.Status == "ready" { break } time.Sleep(5 * time.Millisecond) } js := s.stateJSON() if !strings.Contains(js, `"tasks"`) { t.Fatalf("planning payload missing tasks object: %s", js) } if !strings.Contains(js, `"title":"Write the spec"`) { t.Fatalf("planning payload missing task title: %s", js) } } ``` - [ ] **Step 2: Run the test to verify it fails** Run: `go test ./internal/web/ -run TestPlanningStatePayloadCarriesTasks -v` Expected: FAIL — `undefined: tasks` / `s.ctrl.SetTasks undefined` until the import resolves and the controller exposes the method (the method exists from Task 2, so the only failure here would be a missing import; if Task 2 is complete this compiles and the assertion drives correctness). - [ ] **Step 3: Wire the adapter into the daemon** In `cmd/antidriftd/main.go`, add `"antidrift/internal/tasks"` to the import block. Then, immediately after the AI-wiring block (after the `if backend, err := ai.NewBackend(...) { … } else { … }` block closes), add: ```go // Wire the Tasks port: Amazing Marvin via ampy's `am` CLI. The command is // overridable with ANTIDRIFT_MARVIN_CMD (e.g. "uv run am" or an absolute // path). A missing or failing CLI degrades to no tasks panel at fetch time — // planning still works. ctrl.SetTasks(tasks.NewMarvin(os.Getenv("ANTIDRIFT_MARVIN_CMD"))) log.Printf("tasks: marvin adapter (am)") ``` (`os` and `log` are already imported in `main.go`.) - [ ] **Step 4: Run the web test to verify it passes** Run: `go test ./internal/web/ -run TestPlanningStatePayloadCarriesTasks -v` Expected: PASS. - [ ] **Step 5: Verify the daemon builds** Run: `go build ./cmd/antidriftd/` Expected: builds with no output. - [ ] **Step 6: Commit** ```bash git add cmd/antidriftd/main.go internal/web/web_test.go git commit -m "$(cat <<'EOF' Wire Marvin tasks adapter into the daemon main constructs the Marvin adapter (command overridable via ANTIDRIFT_MARVIN_CMD) and injects it. Adds a web test asserting the planning state payload carries today's tasks. Co-Authored-By: Claude Opus 4.8 EOF )" ``` --- ## Task 4: Planning UI — today's tasks as seed chips **Files:** - Modify: `internal/web/static/app.js` - Modify: `internal/web/static/app.css` This task is presentational; the data path is already covered by the Task 3 web test. There is no JS test harness in this project (consistent with M4), so verify by build/test plus the manual checklist below. - [ ] **Step 1: Add the `updatePlanningTasks` function** In `internal/web/static/app.js`, immediately after the `updatePlanningCoach` function definition (before `function render(state)`), add: ```js // updatePlanningTasks renders today's Marvin tasks as clickable seed chips. // Clicking a chip fills the intent field; the coach pipeline is unchanged. // idle/error/empty render nothing; pending shows a quiet loading line. function updatePlanningTasks(tasks) { const el = document.getElementById('tasksBand'); if (!el) return; if (!tasks || tasks.status === 'idle' || tasks.status === 'error') { el.innerHTML = ''; return; } if (tasks.status === 'pending') { el.innerHTML = `
loading tasks…
`; return; } const list = tasks.tasks || []; if (!list.length) { el.innerHTML = ''; return; } const chips = list.map((t, i) => ``).join(''); el.innerHTML = `
${chips}
`; el.querySelectorAll('.task-chip').forEach(btn => { btn.onclick = () => { const intent = document.getElementById('intent'); if (intent) { intent.value = list[+btn.dataset.i].title; intent.focus(); } }; }); } ``` (Task titles are interpolated into `innerHTML` exactly as the existing coach/evidence rendering does. The titles originate from the user's own Marvin database; this carries the same pre-existing self-XSS posture as the rest of the UI and introduces no new untrusted source — out of scope to change here.) - [ ] **Step 2: Add the tasks band to the planning render** In the planning branch of `render` (`} else if (rs === 'planning') {`), add a tasks band placeholder between the intent band and the "Next action" band. Change: ```js
``` to: ```js
``` - [ ] **Step 3: Call `updatePlanningTasks` from both render paths** In the planning partial-update early-return at the top of `render`, change: ```js if (rs === 'planning' && renderedState === 'planning') { updatePlanningCoach(state.coach); return; } ``` to: ```js if (rs === 'planning' && renderedState === 'planning') { updatePlanningCoach(state.coach); updatePlanningTasks(state.tasks); return; } ``` And at the end of the full planning render branch, change the trailing: ```js updatePlanningCoach(state.coach); } else if (rs === 'active') { ``` to: ```js updatePlanningCoach(state.coach); updatePlanningTasks(state.tasks); } else if (rs === 'active') { ``` - [ ] **Step 4: Add the chip styling** Append to `internal/web/static/app.css`: ```css /* Planning: today's tasks as clickable seed chips */ .tasklist { display: flex; flex-wrap: wrap; gap: 8px; } .task-chip { padding: 6px 10px; border: 1px solid var(--line); border-radius: 999px; background: var(--bg); color: var(--ink); font: inherit; font-size: 13px; cursor: pointer; text-align: left; } .task-chip:hover { border-color: var(--accent); color: var(--accent); } ``` - [ ] **Step 5: Verify assets still serve and the full suite is race-clean** Run: `go vet ./... && go test -race ./...` Expected: PASS across all packages (the embedded-asset and planning-payload tests cover the wiring; JS/CSS are presentational). - [ ] **Step 6: Manual visual check (by eye)** Build and run the daemon (`go run ./cmd/antidriftd/`) with `am` available, click **Start planning**, and confirm: a "Today" band shows task chips; clicking a chip fills the intent field; **Sharpen** then drives the coach as before. With `am` absent, the band stays empty and planning works normally. - [ ] **Step 7: Commit** ```bash git add internal/web/static/app.js internal/web/static/app.css git commit -m "$(cat <<'EOF' Show today's tasks as seed chips on the planning screen The planning view renders Marvin's today list as clickable chips; clicking one fills the intent field, feeding the existing coach flow. idle/error/empty render nothing, pending shows a quiet loading line. Co-Authored-By: Claude Opus 4.8 EOF )" ``` --- ## Final Verification After all tasks: - [ ] `go vet ./... && go test -race ./...` is clean. - [ ] `internal/tasks` imports only `context`, `encoding/json`, and stdlib `os/exec`/`bytes`/`fmt`/`strings` — nothing from `domain`, `session`, `evidence`, or `web` (leaf package preserved). - [ ] No new POST routes; the seed click is client-only. - [ ] No writeback to Marvin (read-only, per spec §7).