Phase 1 app: session list, session screen, spawn, QR enrollment over pinned TLS

Compose app mirroring local-updater's stack (single :androidApp module,
pinned CA, HttpURLConnection transport) plus what this app needs on top:
a bearer token sealed with an Android Keystore AES-GCM key, an
aiapp://enroll intent filter so scanning the server's terminal QR with
the stock camera enrolls the phone with no QR library, an SSE client
that resumes by transcript cursor, and a transcript renderer folding the
common event model into user bubbles, streaming text, collapsible tool
cards, and answerable question cards.

Verified on the tdep emulator against the real server: enrollment deep
link, list, spawn, streamed echo turn, question answer round trip, tool
card expansion, adjustResize keyboard behavior. Build is warning-clean
(compose.* accessors replaced with direct dependencies).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw

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

@@ -0,0 +1,105 @@
+package com.example.aiapp
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+// The session kinds this build can spawn. Phase 2 adds "claude" (with
+// model / working directory / permission-mode fields), phase 4 "pi" --
+// extending this list and the per-kind fields, not adding a parallel
+// screen.
+private val KINDS = listOf("echo")
+
+/** The spawn screen: kind, title, go. */
+@Composable
+fun SpawnScreen(
+    settings: ServerSettings,
+    onSpawned: (SessionSummary) -> Unit,
+    onBack: () -> Unit,
+) {
+    val scope = rememberCoroutineScope()
+    var kind by remember { mutableStateOf(KINDS.first()) }
+    var title by remember { mutableStateOf("") }
+    var busy by remember { mutableStateOf(false) }
+    var error by remember { mutableStateOf<String?>(null) }
+
+    Column(Modifier.fillMaxSize().padding(16.dp)) {
+        Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+            Text(
+                "New session",
+                style = MaterialTheme.typography.headlineSmall,
+                modifier = Modifier.weight(1f),
+            )
+            TextButton(onClick = onBack) { Text("Cancel") }
+        }
+        Spacer(Modifier.height(16.dp))
+
+        Text("Kind", style = MaterialTheme.typography.labelLarge)
+        Row {
+            KINDS.forEach { candidate ->
+                FilterChip(
+                    selected = kind == candidate,
+                    onClick = { kind = candidate },
+                    label = { Text(candidate) },
+                )
+                Spacer(Modifier.height(0.dp))
+            }
+        }
+        Spacer(Modifier.height(16.dp))
+
+        OutlinedTextField(
+            value = title,
+            onValueChange = { title = it },
+            label = { Text("Title") },
+            placeholder = { Text("Echo session") },
+            singleLine = true,
+            modifier = Modifier.fillMaxWidth(),
+        )
+        Spacer(Modifier.height(24.dp))
+
+        error?.let {
+            Text(it, color = MaterialTheme.colorScheme.error)
+            Spacer(Modifier.height(8.dp))
+        }
+
+        Button(
+            onClick = {
+                busy = true
+                scope.launch {
+                    try {
+                        val spawned = withContext(Dispatchers.IO) {
+                            spawnSession(settings, kind, title.trim())
+                        }
+                        onSpawned(spawned)
+                    } catch (e: ApiException) {
+                        error = e.message
+                        busy = false
+                    }
+                }
+            },
+            enabled = !busy,
+        ) { Text(if (busy) "Spawning..." else "Spawn") }
+    }
+}