feat(rounddetail): port the cu-11 round detail screen

CHANGELOG.md

@@ -9,6 +9,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Round detail screen (cu-11): a static, full-screen view reached from
+  the history list with the result banner, the three-up stats grid, the
+  crash position bar, the round timeline, a collapsible provably-fair
+  block whose seeds copy to the clipboard, and the audit-log reference.
+  Replaces the round detail placeholder in the nav graph.
 - Profile screen (cu-15): `ProfileViewModel` maps the signed-in
   `AuthRepository.currentUser` into the identity block (name, email,
   Google provider, avatar monogram); the P&L summary and game-activity

app/src/androidTest/java/com/plainstudio/stackcasino/feature/rounddetail/RoundDetailScreenTest.kt

@@ -0,0 +1,63 @@
+package com.plainstudio.stackcasino.feature.rounddetail
+
+import androidx.compose.ui.test.assertCountEquals
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onAllNodesWithText
+import androidx.compose.ui.test.onNodeWithContentDescription
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.compose.ui.test.performScrollTo
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.plainstudio.stackcasino.ui.theme.StackcasinoTheme
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class RoundDetailScreenTest {
+    @get:Rule
+    val composeRule = createComposeRule()
+
+    private fun setScreen(onBack: () -> Unit = {}) {
+        composeRule.setContent {
+            StackcasinoTheme {
+                RoundDetailScreen(data = roundDetailPreviewData(), onBack = onBack)
+            }
+        }
+    }
+
+    @Test
+    fun renders_the_result_banner_stats_and_timeline() {
+        setScreen()
+
+        composeRule.onNodeWithText("Round Detail").assertIsDisplayed()
+        composeRule.onNodeWithText("+$75.50").assertIsDisplayed()
+        composeRule.onNodeWithText("Crash Point").performScrollTo().assertIsDisplayed()
+        composeRule.onNodeWithText("Timeline").performScrollTo().assertIsDisplayed()
+    }
+
+    @Test
+    fun provably_fair_is_collapsed_until_tapped() {
+        setScreen()
+
+        composeRule.onAllNodesWithText("Server Seed").assertCountEquals(0)
+
+        composeRule.onNodeWithText("Provably Fair").performScrollTo().performClick()
+        composeRule.waitForIdle()
+
+        composeRule.onNodeWithText("Server Seed").performScrollTo().assertIsDisplayed()
+        composeRule.onNodeWithText("Nonce").performScrollTo().assertIsDisplayed()
+    }
+
+    @Test
+    fun back_button_invokes_the_callback() {
+        var backPressed = false
+        setScreen(onBack = { backPressed = true })
+
+        composeRule.onNodeWithContentDescription("Back").performClick()
+
+        assertTrue(backPressed)
+    }
+}

app/src/main/java/com/plainstudio/stackcasino/feature/rounddetail/RoundDetailData.kt

@@ -0,0 +1,134 @@
+package com.plainstudio.stackcasino.feature.rounddetail
+
+import com.plainstudio.stackcasino.model.GameKey
+import com.plainstudio.stackcasino.model.RoundOutcome
+
+/**
+ * Everything the round detail screen renders. The screen is a static
+ * shell for now: [roundDetailPreviewData] mirrors the cu-11 mockup
+ * (mockup/js/screens/round-detail.js) and the live navigation entry
+ * uses it until a rounds repository can resolve a round by id.
+ *
+ * [crashBar] and [safeByLabel] are crash-specific and null for games
+ * that have no cashout-vs-crash visualization.
+ */
+data class RoundDetailData(
+    val game: GameKey,
+    val gameName: String,
+    val headerSubtitle: String,
+    val outcome: RoundOutcome,
+    val netProfitLabel: String,
+    val summaryLabel: String,
+    val stats: List<RoundStat>,
+    val crashBar: CrashBar?,
+    val safeByLabel: String?,
+    val timeline: List<TimelineEvent>,
+    val provablyFair: ProvablyFair,
+    val auditRef: String,
+)
+
+/** One cell in the three-up stats grid. */
+data class RoundStat(
+    val label: String,
+    val value: String,
+    val tone: StatTone,
+)
+
+enum class StatTone { Neutral, Accent, Danger }
+
+/**
+ * Crash position bar: [cashoutFraction] is where the player cashed out
+ * relative to the crash point (which sits at the full width).
+ */
+data class CrashBar(
+    val cashoutFraction: Float,
+    val cashoutLabel: String,
+    val crashLabel: String,
+)
+
+/** One entry in the vertical round timeline. */
+data class TimelineEvent(
+    val label: String,
+    val timeLabel: String,
+    val tone: TimelineTone,
+)
+
+enum class TimelineTone { Neutral, Ok, Danger }
+
+/**
+ * Provably-fair inputs for the round. Each [SeedValue] carries the full
+ * value (copied to the clipboard) plus its display label; the composable
+ * truncates the value for display via [truncateMiddle].
+ */
+data class ProvablyFair(
+    val serverSeed: SeedValue,
+    val clientSeed: SeedValue,
+    val nonce: SeedValue,
+    val hmac: SeedValue,
+    val derivation: String,
+)
+
+data class SeedValue(
+    val label: String,
+    val value: String,
+)
+
+/**
+ * Shortens a long opaque value to `head...tail` with an ellipsis in the
+ * middle, leaving short values untouched. Used for the provably-fair
+ * seeds and hash so the full value stays one clipboard tap away while
+ * the row keeps a single line.
+ */
+internal fun truncateMiddle(
+    value: String,
+    keepHead: Int = SEED_KEEP_HEAD,
+    keepTail: Int = SEED_KEEP_TAIL,
+): String =
+    if (value.length <= keepHead + keepTail + 1) {
+        value
+    } else {
+        value.take(keepHead) + "…" + value.takeLast(keepTail)
+    }
+
+private const val SEED_KEEP_HEAD = 8
+private const val SEED_KEEP_TAIL = 8
+
+internal fun roundDetailPreviewData(): RoundDetailData =
+    RoundDetailData(
+        game = GameKey.Crash,
+        gameName = "Crash",
+        headerSubtitle = "Crash · #48291 · 19s · USDC",
+        outcome = RoundOutcome.Win,
+        netProfitLabel = "+$75.50",
+        summaryLabel = "Bet $50.00 · Payout $125.50",
+        stats =
+            listOf(
+                RoundStat(label = "Bet", value = "$50.00", tone = StatTone.Neutral),
+                RoundStat(label = "Cashed Out", value = "2.51x", tone = StatTone.Accent),
+                RoundStat(label = "Crash Point", value = "3.18x", tone = StatTone.Danger),
+            ),
+        crashBar =
+            CrashBar(
+                cashoutFraction = 0.789f,
+                cashoutLabel = "2.51x",
+                crashLabel = "3.18x",
+            ),
+        safeByLabel = "Safe by 2.1s",
+        timeline =
+            listOf(
+                TimelineEvent("Round started", "7:30:00 AM", TimelineTone.Neutral),
+                TimelineEvent("Bet placed · $50.00", "7:30:01 AM", TimelineTone.Neutral),
+                TimelineEvent("Cash out at 2.51x", "7:30:14 AM", TimelineTone.Ok),
+                TimelineEvent("Crashed at 3.18x", "7:30:19 AM", TimelineTone.Danger),
+                TimelineEvent("Payout credited · $125.50", "7:30:19 AM", TimelineTone.Ok),
+            ),
+        provablyFair =
+            ProvablyFair(
+                serverSeed = SeedValue("Server Seed", "a3f8c2e1b4d79f6a0c3e8b12"),
+                clientSeed = SeedValue("Client Seed", "7e2d4f8a1c3b5d9e0f2a6c84"),
+                nonce = SeedValue("Nonce", "48291"),
+                hmac = SeedValue("HMAC-SHA256 Hash", "e4a7f2c8d1b36e9a0f5c2d84a7b1e3f8c6d0a9b2e5f4"),
+                derivation = "Result derived from HMAC-SHA256(server_seed, client_seed:nonce)",
+            ),
+        auditRef = "AUD-98412",
+    )