test: poll_running_apps parsing against SYNTHETIC activity-recents fixture (A= and I= patterns; real R6 capture still outstanding)

tests/fixtures/activity_recents_synthetic.txt

@@ -0,0 +1,12 @@
+SYNTHETIC fixture — not a real device capture. The real Shield `dumpsys
+activity recents` capture (R6) is still outstanding; this file pins the
+parsing contract of AdbClientBase.poll_running_apps in the meantime, covering
+both the A=uid:package and the I=package/activity fallback patterns.
+Represents the post-grep output of:
+  dumpsys activity recents 2>/dev/null | grep -E 'Recent #|realActivity|visible='
+Note: line order = recency order (most recently used first).
+* Recent #0: Task{2c9f81f #817 type=standard A=10185:ar.tvplayer.tv I=ar.tvplayer.tv/.ui.MainActivity ... visible=true numActivities=1 ...}
+* Recent #1: Task{3dae20b #802 type=standard A=10106:com.github.damontecres.wholphin ...  visible=false numActivities=1 ...}
+* Recent #2: Task{4b7ce01 #788 type=standard I=com.example.launcherapp/.ui.HomeActivity ... visible=true ...}
+* Recent #3: Task{5c8dd12 #770 type=standard A=1000:com.android.systemui ... visible=true ...}
+* Recent #4: Task{6d9ef23 #750 type=unknown A=10003:.HiddenInternalTask ... visible=true ...}