morning: an item can be optional, so a skipped stretch is not a skipped pill (V-473)

Item carried only Key, FactKey and Label, so every checklist entry was
implicitly required and behaviour 1 of #280 could not hold at all. It was not
thin config — there was no field to set.

Item.Optional, `"optional": true` in the routine config, default false, so a
routine written before today behaves exactly as it did. Due now fires on a
missing required item and not on an optional one, and the optional stragglers
still travel in Missing so the one message per day per routine can name them
after the required ones, in softer words.

Evidence, the window and the day plan treat both kinds alike. A missing
optional item is still missing — it just does not earn a nudge, because a
checklist where everything is mandatory is one he learns to ignore.

internal/config/config.go

@@ -601,6 +601,9 @@ type MorningRoutineItemConfig struct {
 	Key     string `json:"key"`
 	FactKey string `json:"fact_key"`
 	Label   string `json:"label"`
+	// Optional — this one being skipped does not earn a nudge. Default false,
+	// so a routine written before 04-08-2026 keeps behaving as it did.
+	Optional bool `json:"optional,omitempty"`
 }
 
 // QuietHoursConfig — a recurring daily quiet-window. Times are local to the
@@ -1734,7 +1737,7 @@ func morningRoutinesFromConfig(mc []MorningRoutineConfig) []morning.Routine {
 	for i, r := range mc {
 		items := make([]morning.Item, len(r.Items))
 		for j, it := range r.Items {
-			items[j] = morning.Item{Key: it.Key, FactKey: it.FactKey, Label: it.Label}
+			items[j] = morning.Item{Key: it.Key, FactKey: it.FactKey, Label: it.Label, Optional: it.Optional}
 		}
 		weekdays := make([]time.Weekday, len(r.Weekdays))
 		for j, w := range r.Weekdays {

internal/morning/morning.go

@@ -30,6 +30,18 @@ type Item struct {
 	Key     string
 	FactKey string
 	Label   string // RU text surfaced when this item is still missing.
+	// Optional — a missing one is not worth a nudge on its own.
+	//
+	// Every item was implicitly required until 04-08-2026, because there was
+	// no field, so a skipped stretch read exactly like skipped medication and
+	// #280's first behaviour could not hold (Vikunja #473). A checklist where
+	// everything is mandatory is a checklist he learns to ignore.
+	//
+	// It changes two things and nothing else: an all-optional routine never
+	// nudges, and a nudge that does fire names the optional stragglers after
+	// the required ones, in softer words. Evidence, the window and the day
+	// plan treat both kinds alike — a missing optional item is still missing.
+	Optional bool
 }
 
 // Routine — one daily checklist. WindowStart/WindowEnd are "HH:MM" local
@@ -60,12 +72,37 @@ type Status struct {
 }
 
 // Candidate — a routine that's due for its one-per-day nag: the window has
-// reached NudgeAt and at least one item is still unevidenced.
+// reached NudgeAt and at least one REQUIRED item is still unevidenced. Missing
+// carries the optional stragglers too, so the one message she is allowed per
+// day per routine can mention them; they never cause it.
 type Candidate struct {
 	Routine Routine
 	Missing []Item
 }
 
+// Required reports the missing items that are not optional. The nudge fires on
+// these; the rest ride along.
+func Required(missing []Item) []Item {
+	var out []Item
+	for _, it := range missing {
+		if !it.Optional {
+			out = append(out, it)
+		}
+	}
+	return out
+}
+
+// OptionalOnly is the other half of Required.
+func OptionalOnly(missing []Item) []Item {
+	var out []Item
+	for _, it := range missing {
+		if it.Optional {
+			out = append(out, it)
+		}
+	}
+	return out
+}
+
 // Validate reports the first structural problem with a routine set: missing
 // name/items, an unparseable HH:MM, an inverted window, a duplicate item key
 // within a routine, or an out-of-range weekday. Called at config load so a
@@ -191,7 +228,11 @@ func Due(routines []Routine, facts map[string]store.Fact, last map[string]time.T
 				missing = append(missing, it)
 			}
 		}
-		if len(missing) == 0 {
+		// A day where only the optional items were skipped is a fine day, and
+		// nagging about it is what teaches him to stop listening (Vikunja
+		// #473). The optional ones still travel in Missing so the message can
+		// mention them when it is being sent anyway.
+		if len(Required(missing)) == 0 {
 			continue
 		}
 		if prev, seen := last[r.Name]; seen && sameDay(prev, now) {

internal/morning/morning_test.go

@@ -182,3 +182,40 @@ func TestDueRespectsExplicitNudgeAt(t *testing.T) {
 		t.Fatalf("expected candidate at explicit nudge_at, got %d", len(out))
 	}
 }
+
+// TestOptionalItemsDoNotEarnANudge — behaviour 1 of #280, which could not hold
+// while every item was implicitly required (Vikunja #473).
+func TestOptionalItemsDoNotEarnANudge(t *testing.T) {
+	r := Routine{
+		Name:        "утро",
+		WindowStart: "07:00",
+		WindowEnd:   "10:00",
+		Items: []Item{
+			{Key: "meds", FactKey: "meds", Label: "таблетки"},
+			{Key: "stretch", FactKey: "stretch", Label: "растяжка", Optional: true},
+		},
+	}
+	now := time.Date(2026, 8, 4, 10, 0, 0, 0, time.UTC)
+	took := map[string]store.Fact{"meds": {Key: "meds", Ts: now.Add(-2 * time.Hour)}}
+
+	// Only the stretch was skipped: nothing to say.
+	if due := Due([]Routine{r}, took, map[string]time.Time{}, now); len(due) != 0 {
+		t.Fatalf("an optional item alone must not nudge, got %+v", due)
+	}
+	// The medication was skipped: she says so, and mentions the stretch too.
+	due := Due([]Routine{r}, map[string]store.Fact{}, map[string]time.Time{}, now)
+	if len(due) != 1 {
+		t.Fatalf("a missing required item must nudge, got %+v", due)
+	}
+	if got := Required(due[0].Missing); len(got) != 1 || got[0].Key != "meds" {
+		t.Fatalf("Required = %+v, want the meds item alone", got)
+	}
+	if got := OptionalOnly(due[0].Missing); len(got) != 1 || got[0].Key != "stretch" {
+		t.Fatalf("OptionalOnly = %+v, want the stretch item alone", got)
+	}
+	// The window still reports it as missing — optional is not invisible.
+	st := Evaluate(r, map[string]store.Fact{}, now.Add(-time.Hour))
+	if len(st.Missing) != 2 {
+		t.Fatalf("Evaluate must still list both, got %+v", st.Missing)
+	}
+}