Widget diagnostics: per-intent beacons (keychain slots + relay query)

The single-slot beacon couldn't distinguish small vs medium (last writer
wins). Beacon keychain service now embeds the intent type name so small
and medium never overwrite each other; the relay GET now carries the
intent type + entry state as query params so the access log shows exactly
which widget kind ran makeEntry, when, and with what. Diagnostics screen
shows SMALL and MEDIUM beacons side by side — a missing SMALL beacon
after adding the small widget proves its timeline never reaches the
provider (system-level config resolution failure).

Shared/FuelStore.swift

@@ -697,15 +697,17 @@ struct FuelStore {
         writeKeychain(data: Data(value.utf8), service: service)
     }
 
-    // Widget diagnostics beacon — the widget extension writes its last
-    // makeEntry state here (keychain survives on free SideStore accounts where
-    // the app-group container isn't provisioned); the app's Debug section
-    // reads it to see whether a widget timeline ran and what it produced.
-    static func saveWidgetDiag(_ json: String) {
-        saveString(json, service: "widget.diag")
+    // Widget diagnostics beacons — the widget extension writes its last
+    // makeEntry state PER INTENT TYPE (keychain survives on free SideStore
+    // accounts where the app-group container isn't provisioned); the app's
+    // Debug section reads them to see whether each widget kind's timeline
+    // actually ran and what it produced. Service key embeds the intent type
+    // so small and medium widgets never overwrite each other.
+    static func saveWidgetDiag(_ json: String, intentType: String) {
+        saveString(json, service: "widget.diag.\(intentType)")
     }
 
-    static func loadWidgetDiag() -> String? {
-        loadString(service: "widget.diag")
+    static func loadWidgetDiag(intentType: String) -> String? {
+        loadString(service: "widget.diag.\(intentType)")
     }
 }