feat: sync log, cache clear endpoint, Todoist projects from cached tasks

- migration 016: sync_log table
- store: AddSyncLogEntry, GetRecentSyncLog, InvalidateAllCaches, GetProjectsFromTasks
- settings: HandleClearCache (POST /settings/clear-cache), SyncLog in page data
- settings: use GetProjectsFromTasks instead of deprecated Todoist REST /projects
- handlers: populate atom projects from store
- agent: log warning on registration failure instead of silently swallowing
- google_tasks: simplify URL literal
- tests: sync log CRUD, clear cache handler, settings page includes sync log,
  sync sources adds log entry, incremental sync paths, task completion
  response/headers, calendar cache fallback

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 36 insertions, 14 deletions

diff --git a/internal/handlers/settings.go b/internal/handlers/settings.go
index 0ad362b..c0ba654 100644
--- a/internal/handlers/settings.go
+++ b/internal/handlers/settings.go
@@ -8,12 +8,14 @@ import (
 
 	"task-dashboard/internal/auth"
 	"task-dashboard/internal/models"
+	"task-dashboard/internal/store"
 )
 
 // HandleSettingsPage renders the settings page
 func (h *Handler) HandleSettingsPage(w http.ResponseWriter, r *http.Request) {
 	configs, _ := h.store.GetSourceConfigs()
 	toggles, _ := h.store.GetFeatureToggles()
+	syncLog, _ := h.store.GetRecentSyncLog(20)
 
 	// Group configs by source
 	bySource := make(map[string][]models.SourceConfig)
@@ -25,12 +27,14 @@ func (h *Handler) HandleSettingsPage(w http.ResponseWriter, r *http.Request) {
 		Configs         map[string][]models.SourceConfig
 		Sources         []string
 		Toggles         []models.FeatureToggle
+		SyncLog         []store.SyncLogEntry
 		CSRFToken       string
 		WebAuthnEnabled bool
 	}{
 		Configs:         bySource,
 		Sources:         []string{"trello", "todoist", "gcal", "gtasks"},
 		Toggles:         toggles,
+		SyncLog:         syncLog,
 		CSRFToken:       auth.GetCSRFTokenFromContext(r.Context()),
 		WebAuthnEnabled: h.WebAuthnEnabled,
 	}
@@ -61,21 +65,18 @@ func (h *Handler) HandleSyncSources(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	// Sync Todoist projects
-	if h.todoistClient != nil {
-		projects, err := h.todoistClient.GetProjects(ctx)
-		if err == nil {
-			var items []models.SourceConfig
-			for _, p := range projects {
-				items = append(items, models.SourceConfig{
-					Source:   "todoist",
-					ItemType: "project",
-					ItemID:   p.ID,
-					ItemName: p.Name,
-				})
-			}
-			_ = h.store.SyncSourceConfigs("todoist", "project", items)
+	// Sync Todoist projects from cached tasks (avoids deprecated REST API)
+	if projects, err := h.store.GetProjectsFromTasks(); err == nil && len(projects) > 0 {
+		var items []models.SourceConfig
+		for _, p := range projects {
+			items = append(items, models.SourceConfig{
+				Source:   "todoist",
+				ItemType: "project",
+				ItemID:   p.ID,
+				ItemName: p.Name,
+			})
 		}
+		_ = h.store.SyncSourceConfigs("todoist", "project", items)
 	}
 
 	// Sync Google Calendar calendars
@@ -112,10 +113,31 @@ func (h *Handler) HandleSyncSources(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	_ = h.store.AddSyncLogEntry("sync", "Sources synced")
+
 	// Return updated configs
 	h.HandleSettingsPage(w, r)
 }
 
+// HandleClearCache invalidates all caches and clears the Todoist sync token
+func (h *Handler) HandleClearCache(w http.ResponseWriter, r *http.Request) {
+	if err := h.store.InvalidateAllCaches(); err != nil {
+		JSONError(w, http.StatusInternalServerError, "Failed to clear cache", err)
+		return
+	}
+
+	if err := h.store.ClearSyncToken("todoist"); err != nil {
+		JSONError(w, http.StatusInternalServerError, "Failed to clear sync token", err)
+		return
+	}
+
+	_ = h.store.AddSyncLogEntry("cache_clear", "Cache cleared — next load fetches fresh data")
+
+	syncLog, _ := h.store.GetRecentSyncLog(20)
+	w.Header().Set("HX-Trigger", "refresh-tasks")
+	HTMLResponse(w, h.renderer, "sync-log", syncLog)
+}
+
 // HandleToggleSourceConfig toggles a source config item
 func (h *Handler) HandleToggleSourceConfig(w http.ResponseWriter, r *http.Request) {
 	if err := r.ParseForm(); err != nil {