feat(api-keys): scopes for triage, tasks and list items (FLAW-07)

Keys get scopes when created (webhook:triage, webhook:task,
webhook:list; default triage, old keys become triage). The webhook
ingest learns target task (optional task list) and list_item (needs a
list the owner may write to); /inbox checks the scope of its target as
well; a missing scope answers 403. Keys can no longer open live streams,
which carried all of the owner's events.

The visible key UI lived in the account settings while EcosystemView
was never rendered; it is replaced by ApiKeysPanel in the settings with
scope chips, scope badges per key and a simulator for all three
targets. Examples send the key as X-API-Key header, not in the URL.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/handlers_thoughts.go

@@ -60,6 +60,10 @@ func (s *Server) handleCaptureInbox(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	if !requireDeliveryScope(w, r, strings.TrimSpace(req.Target)) {
+		return
+	}
+
 	thought, err := s.store.CreateThoughtWithDetails(userID, req.Content, req.Priority, source, dueDate, taskListID, "todo", "")
 	if err != nil {
 		writeStoreError(w, http.StatusBadRequest, err)