P-2069 unify mobile screen events as page type (#12)

* feat: unify mobile screen events as page type for Tinybird compatibility

Screen events from the React Native SDK now send type="page" instead of
type="screen", with screen name mapped to page_title, page_path, and
page_url context fields. This allows Tinybird's process_sessions and
process_sources materializations (which filter on type='page') to include
mobile screen views. The channel="mobile" field distinguishes mobile from
web traffic.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: let user-supplied context override default page fields in screen events

User-provided context values for page_title, page_path, and page_url
were being silently discarded because the defaults were spread after the
user context. Reversed the spread order so user values take precedence,
consistent with how generateContext() handles merging.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor: remove redundant page_path from screen event context

Tinybird derives page_path from page_url via path(), so setting it
in the SDK is redundant and never read.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yosriady

src/lib/event/EventFactory.ts

@@ -372,7 +372,10 @@ class EventFactory implements IEventFactory {
   }
 
   /**
-   * Generate screen view event (mobile equivalent of page)
+   * Generate screen view event as a page event for unified analytics.
+   * Maps screen name to page-equivalent context fields (page_title, page_path, page_url)
+   * so Tinybird materializations (process_sessions, process_sources) can process mobile
+   * screen views alongside web page views. The channel="mobile" distinguishes the source.
    */
   async generateScreenEvent(
     name: string,
@@ -382,12 +385,21 @@ class EventFactory implements IEventFactory {
   ): Promise<IFormoEvent> {
     const props = { ...(properties ?? {}), name, ...(category && { category }) };
 
+    // Map screen name to page-equivalent context fields for Tinybird compatibility.
+    // page_path is omitted — Tinybird derives it from page_url via path().
+    // User-supplied context values take precedence (spread last).
+    const screenContext: IFormoEventContext = {
+      page_title: name,
+      page_url: `app://${name}`,
+      ...(context ?? {}),
+    };
+
     const screenEvent: Partial<IFormoEvent> = {
       properties: props,
-      type: "screen",
+      type: "page",
     };
 
-    return this.getEnrichedEvent(screenEvent, context);
+    return this.getEnrichedEvent(screenEvent, screenContext);
   }
 
   async generateDetectWalletEvent(