Mobile notifications for iOS (#210)

* mobile: wire notification registration and listener

* implement backend components for push notifications

* refactor: agentic comment cleanup

* docs: use proper module name for particle processor

* set required env variables for push notifications

* bump version

* fix: always upsert push token on mobile start

* Revert "fix: always upsert push token on mobile start"

This reverts commit 90ff18a788.

* send push notifications regardless of online status

go/internal/handler/billing.go

@@ -25,12 +25,8 @@ type PortalSessionResponse struct {
 	URL string `json:"url"`
 }
 
-// GetNetworkUsage returns the freemium quota state for the authenticated
-// caller's current network: how many messages they've used today, the daily
-// limit (null for pro), and when the counter resets.
-//
-// Authorization: any network member may read (not admin-only) since the UI
-// surfaces this to every sender.
+// GetNetworkUsage reports today's usage, daily limit (nil on pro), and reset
+// time. Open to any network member since the UI surfaces it to every sender.
 func (h *Handler) GetNetworkUsage(w http.ResponseWriter, r *http.Request) {
 	humanId, ok := middleware.HumanIdFromContext(r.Context())
 	if !ok {
@@ -170,8 +166,8 @@ func (h *Handler) HandleStripeWebhook(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 
-// loadNetworkForAdmin resolves the {id} path param and verifies the caller
-// is the network's admin. On failure it writes the HTTP error and returns ok=false.
+// Resolves {id}, verifies the caller is admin. On failure writes the HTTP
+// error and returns ok=false.
 func (h *Handler) loadNetworkForAdmin(w http.ResponseWriter, r *http.Request) (*network.Network, string, bool) {
 	humanId, ok := middleware.HumanIdFromContext(r.Context())
 	if !ok {