stop the disconnected-history alert from blocking scrolling

- Skip older-history loads silently while the connection is down:
  the trigger previously failed with "not connected", popped the
  global alert over the timeline and froze scrolling until dismissed.
- Accept fast reply-swipe flicks whose end state is clearly leftward
  even without an intermediate horizontal lock, while scroll-owned
  touches still never activate the swipe.
- Add a seeded-chat UI test mode (launch argument), accessibility
  identifiers and a LumaUITests target with timeline scroll and reply
  swipe tests; guard the fix in verify.sh.

project.yml

@@ -188,6 +188,19 @@ targets:
         PRODUCT_BUNDLE_IDENTIFIER: app.luma.chat.tests
         GENERATE_INFOPLIST_FILE: true
 
+  LumaUITests:
+    type: bundle.ui-testing
+    platform: iOS
+    deploymentTarget: "17.0"
+    sources:
+      - path: UITests
+    dependencies:
+      - target: Luma
+    settings:
+      base:
+        PRODUCT_BUNDLE_IDENTIFIER: app.luma.chat.uitests
+        GENERATE_INFOPLIST_FILE: true
+
 schemes:
   Luma:
     build:
@@ -200,6 +213,7 @@ schemes:
       config: Debug
       targets:
         - LumaTests
+        - LumaUITests
     archive:
       config: Release
   LumaMac: