app: bench v2 -- a real fling, typing and keyboard phases

Iris's ask after using the Compose bench build on her phone: the old
scroll phase used animateScrollBy, which can only ever cover the fixed
distance/time it's given, so it never flings the way a real fast swipe
does. BenchRun.run now has four phases: fling (8 flings out + 8 back
through the list's own FlingBehavior at 12,000px/s), stream (unchanged),
type (600 fixed characters into the real composer TextFieldValue, then
deleted, to exercise wrapping and the transcript being pushed upward),
and keyboard (five show/hide cycles via WindowInsetsControllerCompat,
each confirmed by isImeVisible rather than assumed).

FrameStats.markPhase/phaseLines slice the same FrameMetrics recording
by phase rather than running a second recorder; debugReport gains a
phaseFrames section ahead of the existing whole-run frames/accounting/
work sections, which are otherwise unchanged.

Also fixes a pre-existing, unrelated break in MainActivity.kt's
benchSessionSummary() -- missing several SessionSummary constructor
arguments from an earlier change -- since it blocked compileBenchKotlin
outright.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

app/androidApp/src/main/kotlin/com/example/aiapp/SessionScreen.kt

@@ -12,6 +12,7 @@ import androidx.activity.result.PickVisualMediaRequest
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.gestures.ScrollableDefaults
 import androidx.compose.foundation.gestures.awaitEachGesture
 import androidx.compose.foundation.gestures.awaitFirstDown
 import androidx.compose.foundation.layout.Box
@@ -64,12 +65,15 @@ import androidx.compose.runtime.snapshots.Snapshot
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.drawWithContent
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.PointerEventPass
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalView
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.TextRange
@@ -354,6 +358,17 @@ fun SessionScreen(
     // `rememberSaveable`, and this screen restores by its own anchor instead -- two restores would
     // fight over the first frame.
     val listState = remember(address) { LazyListState() }
+    // The list's own fling path -- what a real flick decays through -- captured here so BenchRun's
+    // fling phase can drive `LazyListState.scroll` through exactly the `FlingBehavior` this
+    // screen's
+    // `TranscriptList` already uses by not overriding it (its `LazyColumn` takes no `flingBehavior`
+    // argument, so this is the same default it gets).
+    val flingBehavior = ScrollableDefaults.flingBehavior()
+    // Where BenchRun's type phase focuses before it types, and the view it toggles the keyboard on
+    // -- both bench-only, but cheap enough (a remembered object, a CompositionLocal read) to hold
+    // unconditionally rather than behind a second code path only the bench build compiles.
+    val composerFocus = remember { FocusRequester() }
+    val view = LocalView.current
     // Whether the newest message is on screen right now. The list is reversed, so the newest end is
     // the scrolling start: nothing behind you is exactly being at the bottom. Asked of the scroll
     // state rather than of item indices, because a zero-height first item makes an index ambiguous.
@@ -1256,6 +1271,10 @@ fun SessionScreen(
                     FrameStats.drawPhase().let { (nanos, count) -> drawAccounting(nanos, count) },
                 crash = lastCrash(context),
                 extra = extra,
+                // Empty outside a BenchRun.run pass -- copyRenderReport's own reset below clears
+                // the
+                // marks along with everything else, so an ordinary copy never has any to show.
+                phaseFrames = FrameStats.phaseLines(context.refreshHz()),
             )
         context.copyToClipboard("ai-app render report", report)
         // Also to the log, so a session driving the app over adb can read the same report the
@@ -1270,15 +1289,24 @@ fun SessionScreen(
         Toast.makeText(context, "Copied render report", Toast.LENGTH_SHORT).show()
     }
     val copyRenderReport = { buildAndCopyReport() }
-    // Bench build only: P0's scripted scroll-and-stream benchmark (BenchRun.kt), against the
-    // fixture session opened below instead of a real server. Null everywhere else -- see
+    // Bench build only: P0's scripted fling/stream/type/keyboard benchmark (BenchRun.kt), against
+    // the fixture session opened below instead of a real server. Null everywhere else -- see
     // [SessionSettingsDialog]'s onRunBenchmark.
     val runBenchmark: (() -> Unit)? =
         if (BuildConfig.FIXTURE_MODE) {
             {
                 settingsOpen = false
                 scope.launch {
-                    val extra = BenchRun.run(context, scope, listState)
+                    val extra =
+                        BenchRun.run(
+                            context = context,
+                            scope = scope,
+                            listState = listState,
+                            flingBehavior = flingBehavior,
+                            composerFocus = composerFocus,
+                            setComposerText = { text -> input = atEnd(text) },
+                            view = view,
+                        )
                     buildAndCopyReport(extra)
                 }
             }
@@ -1777,7 +1805,10 @@ fun SessionScreen(
                             input = it
                             saveDraft(context, summary.id, it.text)
                         },
-                        modifier = Modifier.fillMaxWidth(),
+                        // BenchRun's type phase requests focus on this exact field
+                        // (`composerFocus`)
+                        // so it types through the real composer rather than a stand-in.
+                        modifier = Modifier.fillMaxWidth().focusRequester(composerFocus),
                         // No longer "(+image)": the images are on screen above this, and a
                         // placeholder saying so said it in words beside the thing itself.
                         placeholder = { Text("Message") },