Improve timeline view with dynamic bounds, now line, and overlap handling

- Add dynamic calendar clipping: show 1 hour before/after events instead of hardcoded 6am-10pm
- Add "NOW" line indicator showing current time position
- Improve time label readability with larger font and better contrast
- Add overlap detection with column-based indentation for concurrent events
- Apply calendar view to Tomorrow section (matching Today's layout)
- Fix auto-refresh switching to tasks tab (default was 'tasks' instead of 'timeline')

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

3 files changed, 100 insertions, 3 deletions

diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index bba12ad..c384c48 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -36,8 +36,13 @@ type Handler struct {
 
 // New creates a new Handler instance
 func New(s *store.Store, todoist api.TodoistAPI, trello api.TrelloAPI, planToEat api.PlanToEatAPI, googleCalendar api.GoogleCalendarAPI, googleTasks api.GoogleTasksAPI, cfg *config.Config) *Handler {
+	// Template functions
+	funcMap := template.FuncMap{
+		"subtract": func(a, b int) int { return a - b },
+	}
+
 	// Parse templates including partials
-	tmpl, err := template.ParseGlob(filepath.Join(cfg.TemplateDir, "*.html"))
+	tmpl, err := template.New("").Funcs(funcMap).ParseGlob(filepath.Join(cfg.TemplateDir, "*.html"))
 	if err != nil {
 		log.Printf("Warning: failed to parse templates: %v", err)
 	}
diff --git a/internal/handlers/handlers_test.go b/internal/handlers/handlers_test.go
index 3367ef6..96cb911 100644
--- a/internal/handlers/handlers_test.go
+++ b/internal/handlers/handlers_test.go
@@ -64,11 +64,16 @@ func setupTestDB(t *testing.T) (*store.Store, func()) {
 func loadTestTemplates(t *testing.T) *template.Template {
 	t.Helper()
 
+	// Template functions (must match handlers.go)
+	funcMap := template.FuncMap{
+		"subtract": func(a, b int) int { return a - b },
+	}
+
 	// Get path relative to project root
-	tmpl, err := template.ParseGlob(filepath.Join("web", "templates", "*.html"))
+	tmpl, err := template.New("").Funcs(funcMap).ParseGlob(filepath.Join("web", "templates", "*.html"))
 	if err != nil {
 		// Try from internal/handlers (2 levels up)
-		tmpl, err = template.ParseGlob(filepath.Join("..", "..", "web", "templates", "*.html"))
+		tmpl, err = template.New("").Funcs(funcMap).ParseGlob(filepath.Join("..", "..", "web", "templates", "*.html"))
 		if err != nil {
 			t.Logf("Warning: failed to parse templates: %v", err)
 			return nil
diff --git a/internal/handlers/timeline.go b/internal/handlers/timeline.go
index 5e583d6..fa5bcec 100644
--- a/internal/handlers/timeline.go
+++ b/internal/handlers/timeline.go
@@ -21,6 +21,19 @@ type TimelineData struct {
 	TodayLabel    string // e.g., "Today - Monday"
 	TomorrowLabel string // e.g., "Tomorrow - Tuesday"
 	LaterLabel    string // e.g., "Wednesday, Jan 29"
+
+	// Calendar view bounds (1 hour before first event, 1 hour after last)
+	TodayStartHour int
+	TodayEndHour   int
+	TodayHours     []int // Slice of hours to render
+
+	TomorrowStartHour int
+	TomorrowEndHour   int
+	TomorrowHours     []int
+
+	// Current time for "now" line
+	NowHour   int
+	NowMinute int
 }
 
 // HandleTimeline renders the timeline view
@@ -70,6 +83,8 @@ func (h *Handler) HandleTimeline(w http.ResponseWriter, r *http.Request) {
 		TodayLabel:    "Today - " + now.Format("Monday"),
 		TomorrowLabel: "Tomorrow - " + tomorrow.Format("Monday"),
 		LaterLabel:    dayAfterTomorrow.Format("Monday, Jan 2") + "+",
+		NowHour:       now.Hour(),
+		NowMinute:     now.Minute(),
 	}
 	for _, item := range items {
 		switch item.DaySection {
@@ -82,5 +97,77 @@ func (h *Handler) HandleTimeline(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// Calculate calendar bounds for Today (1 hour buffer before/after timed events)
+	data.TodayStartHour, data.TodayEndHour = calcCalendarBounds(data.TodayItems, now.Hour())
+	for h := data.TodayStartHour; h <= data.TodayEndHour; h++ {
+		data.TodayHours = append(data.TodayHours, h)
+	}
+
+	// Calculate calendar bounds for Tomorrow
+	data.TomorrowStartHour, data.TomorrowEndHour = calcCalendarBounds(data.TomorrowItems, -1)
+	for h := data.TomorrowStartHour; h <= data.TomorrowEndHour; h++ {
+		data.TomorrowHours = append(data.TomorrowHours, h)
+	}
+
 	HTMLResponse(w, h.templates, "timeline-tab", data)
 }
+
+// calcCalendarBounds returns start/end hours for calendar view based on timed events.
+// If currentHour >= 0, it's included in the range (for "now" line visibility).
+// Returns hours clamped to 0-23 with 1-hour buffer before/after events.
+func calcCalendarBounds(items []models.TimelineItem, currentHour int) (startHour, endHour int) {
+	minHour := 23
+	maxHour := 0
+	hasTimedEvents := false
+
+	for _, item := range items {
+		// Skip all-day/overdue items (midnight with no real time)
+		if item.IsAllDay || item.IsOverdue {
+			continue
+		}
+		h := item.Time.Hour()
+		// Skip midnight items unless they have an end time
+		if h == 0 && item.Time.Minute() == 0 && item.EndTime == nil {
+			continue
+		}
+		hasTimedEvents = true
+		if h < minHour {
+			minHour = h
+		}
+		endH := h
+		if item.EndTime != nil {
+			endH = item.EndTime.Hour()
+		}
+		if endH > maxHour {
+			maxHour = endH
+		}
+	}
+
+	// Include current hour if provided
+	if currentHour >= 0 {
+		hasTimedEvents = true
+		if currentHour < minHour {
+			minHour = currentHour
+		}
+		if currentHour > maxHour {
+			maxHour = currentHour
+		}
+	}
+
+	if !hasTimedEvents {
+		// Default: show 8am-6pm
+		return 8, 18
+	}
+
+	// Add 1 hour buffer, clamp to valid range
+	startHour = minHour - 1
+	if startHour < 0 {
+		startHour = 0
+	}
+	endHour = maxHour + 1
+	if endHour > 23 {
+		endHour = 23
+	}
+
+	return startHour, endHour
+}