Refactor AuthService login logic

Extracted complex logic from `AuthService.login` into private helper methods (`_validateAndNormalizeLoginInputs`, `_checkAccessControl`, `_updateGlobalState`, `_updateSavedProfiles`, `_initiatePostLogin`) to improve readability and maintainability.

Moved `SimpleEventEmitter` to `js/utils/simpleEventEmitter.js` and auth constants/normalization helpers to `js/services/authUtils.js` to reduce file size and coupling.

Co-authored-by: PR0M3TH3AN <[email protected]>

js/services/authUtils.js

@@ -0,0 +1,53 @@
+
+export const FALLBACK_PROFILE = {
+  name: "Unknown",
+  picture: "assets/svg/default-profile.svg",
+  about: "",
+  website: "",
+  banner: "",
+  lud16: "",
+  lud06: "",
+};
+
+export const FAST_PROFILE_RELAY_LIMIT = 3;
+export const FAST_PROFILE_TIMEOUT_MS = 2500;
+export const BACKGROUND_PROFILE_TIMEOUT_MS = 6000;
+
+export function normalizeProviderId(providerId) {
+  return typeof providerId === "string" && providerId.trim()
+    ? providerId.trim()
+    : "nip07";
+}
+
+export function normalizeAuthType(authTypeCandidate, providerId, providerResult) {
+  const candidates = [];
+
+  if (typeof authTypeCandidate === "string") {
+    candidates.push(authTypeCandidate);
+  }
+
+  if (providerResult && typeof providerResult === "object") {
+    const resultAuthType = providerResult.authType;
+    if (typeof resultAuthType === "string") {
+      candidates.push(resultAuthType);
+    }
+
+    const resultProviderId = providerResult.providerId;
+    if (typeof resultProviderId === "string") {
+      candidates.push(resultProviderId);
+    }
+  }
+
+  if (typeof providerId === "string") {
+    candidates.push(providerId);
+  }
+
+  for (const candidate of candidates) {
+    const trimmed = candidate.trim();
+    if (trimmed) {
+      return trimmed;
+    }
+  }
+
+  return "nip07";
+}