Expand agent context API with completed log and calendar view

- Add completed_tasks table to log task completions with title, due date,
  and completion timestamp
- Extend agent context date range: 7 days back to 14 days forward
- Add completed_log to API response (last 50 completed tasks)
- Add day_section field to timeline items (overdue/today/tomorrow/later)
- Add calendar-style view for today's schedule (6am-10pm hourly grid)
- Add tabbed interface for Timeline vs Completed Log in HTML view

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

1 files changed, 20 insertions, 8 deletions

diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 9fe1b2c..0e5edcc 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -673,8 +673,11 @@ func (h *Handler) handleAtomToggle(w http.ResponseWriter, r *http.Request, compl
 	}
 
 	if complete {
-		// Get task title before removing from cache
-		title := h.getAtomTitle(id, source)
+		// Get task details before removing from cache
+		title, dueDate := h.getAtomDetails(id, source)
+
+		// Log to completed tasks
+		_ = h.store.SaveCompletedTask(source, id, title, dueDate)
 
 		// Remove from local cache
 		switch source {
@@ -706,14 +709,14 @@ func (h *Handler) handleAtomToggle(w http.ResponseWriter, r *http.Request, compl
 	}
 }
 
-// getAtomTitle retrieves the title for a task/card/bug from the store
-func (h *Handler) getAtomTitle(id, source string) string {
+// getAtomDetails retrieves title and due date for a task/card/bug from the store
+func (h *Handler) getAtomDetails(id, source string) (string, *time.Time) {
 	switch source {
 	case "todoist":
 		if tasks, err := h.store.GetTasks(); err == nil {
 			for _, t := range tasks {
 				if t.ID == id {
-					return t.Content
+					return t.Content, t.DueDate
 				}
 			}
 		}
@@ -722,7 +725,7 @@ func (h *Handler) getAtomTitle(id, source string) string {
 			for _, b := range boards {
 				for _, c := range b.Cards {
 					if c.ID == id {
-						return c.Name
+						return c.Name, c.DueDate
 					}
 				}
 			}
@@ -733,13 +736,22 @@ func (h *Handler) getAtomTitle(id, source string) string {
 			if _, err := fmt.Sscanf(id, "bug-%d", &bugID); err == nil {
 				for _, b := range bugs {
 					if b.ID == bugID {
-						return b.Description
+						return b.Description, nil
 					}
 				}
 			}
 		}
+	case "gtasks":
+		// Google Tasks don't have local cache, return generic title
+		return "Google Task", nil
 	}
-	return "Task"
+	return "Task", nil
+}
+
+// getAtomTitle retrieves the title for a task/card/bug from the store (legacy)
+func (h *Handler) getAtomTitle(id, source string) string {
+	title, _ := h.getAtomDetails(id, source)
+	return title
 }
 
 // HandleUnifiedAdd creates a task in Todoist or a card in Trello from the Quick Add form