fix(core): Revert sendSession consolidation and URLSearchParams changes

Revert two optimizations that caused CI failures:

- sendSession consolidation (client.ts): The eager `session.attrs = session.attrs || {}`
  added an empty `attrs` property to session aggregates, breaking node-core
  httpServerIntegration tests that assert on the exact shape.

- getReportDialogEndpoint URLSearchParams (api.ts): URLSearchParams percent-encodes
  the DSN value (`://` → `%3A%2F%2F`), changing output format vs the original raw
  string concatenation approach. Core API tests compare exact URL strings.

Both changes were functionally equivalent at runtime but broke snapshot-style
test assertions in other packages.

Co-Authored-By: Claude claude@anthropic.com

Author: HazAT

packages/core/src/api.ts

@@ -53,25 +53,32 @@ export function getReportDialogEndpoint(dsnLike: DsnLike, dialogOptions: ReportD
   }
 
   const endpoint = `${getBaseApiEndpoint(dsn)}embed/error-page/`;
-  const params = new URLSearchParams({ dsn: dsnToString(dsn) });
 
+  let encodedOptions = `dsn=${dsnToString(dsn)}`;
   for (const key in dialogOptions) {
-    if (key === 'dsn' || key === 'onClose') {
+    if (key === 'dsn') {
+      continue;
+    }
+
+    if (key === 'onClose') {
       continue;
     }
 
     if (key === 'user') {
       const user = dialogOptions.user;
-      if (user?.name) {
-        params.set('name', user.name);
+      if (!user) {
+        continue;
+      }
+      if (user.name) {
+        encodedOptions += `&name=${encodeURIComponent(user.name)}`;
       }
-      if (user?.email) {
-        params.set('email', user.email);
+      if (user.email) {
+        encodedOptions += `&email=${encodeURIComponent(user.email)}`;
       }
     } else {
-      params.set(key, dialogOptions[key] as string);
+      encodedOptions += `&${encodeURIComponent(key)}=${encodeURIComponent(dialogOptions[key] as string)}`;
     }
   }
 
-  return `${endpoint}?${params.toString()}`;
+  return `${endpoint}?${encodedOptions}`;
 }

packages/core/src/client.ts

@@ -534,16 +534,24 @@ export abstract class Client<O extends ClientOptions = ClientOptions> {
   public sendSession(session: Session | SessionAggregates): void {
     // Backfill release and environment on session
     const { release: clientReleaseOption, environment: clientEnvironmentOption = DEFAULT_ENVIRONMENT } = this._options;
-    const target = 'aggregates' in session ? (session.attrs = session.attrs || {}) : session;
-
-    if (!target.release && !clientReleaseOption) {
-      DEBUG_BUILD && debug.warn(MISSING_RELEASE_FOR_SESSION_ERROR);
-      return;
+    if ('aggregates' in session) {
+      const sessionAttrs = session.attrs || {};
+      if (!sessionAttrs.release && !clientReleaseOption) {
+        DEBUG_BUILD && debug.warn(MISSING_RELEASE_FOR_SESSION_ERROR);
+        return;
+      }
+      sessionAttrs.release = sessionAttrs.release || clientReleaseOption;
+      sessionAttrs.environment = sessionAttrs.environment || clientEnvironmentOption;
+      session.attrs = sessionAttrs;
+    } else {
+      if (!session.release && !clientReleaseOption) {
+        DEBUG_BUILD && debug.warn(MISSING_RELEASE_FOR_SESSION_ERROR);
+        return;
+      }
+      session.release = session.release || clientReleaseOption;
+      session.environment = session.environment || clientEnvironmentOption;
     }
 
-    target.release = target.release || clientReleaseOption;
-    target.environment = target.environment || clientEnvironmentOption;
-
     this.emit('beforeSendSession', session);
 
     const env = createSessionEnvelope(session, this._dsn, this._options._metadata, this._options.tunnel);