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/DebugStats.kt

@@ -134,6 +134,13 @@ fun debugReport(
      * render-report button reads exactly as it did before this existed.
      */
     extra: List<String> = emptyList(),
+    /**
+     * Bench v2's per-phase frame accounting ([FrameStats.phaseLines]) --
+     * fling/stream/type/keyboard, each a slice of the same frames the whole-run sections below
+     * still cover in full. Empty on every path but the scripted bench run, same reasoning as
+     * [extra].
+     */
+    phaseFrames: List<String> = emptyList(),
 ): String = buildString {
     appendLine("ai-app render report")
     appendLine(device)
@@ -148,6 +155,11 @@ fun debugReport(
     appendLine("transcript:")
     transcript.forEach { appendLine(it) }
     appendLine()
+    if (phaseFrames.isNotEmpty()) {
+        appendLine("per phase:")
+        phaseFrames.forEach { appendLine(it) }
+        appendLine()
+    }
     appendLine("frames:")
     frames.forEach { appendLine(it) }
     appendLine()