ai-app: a phone interface to Claude Code and llama.cpp sessions

A Rust backend that owns the sessions and an Android app that reads them.
The server spawns and adopts CLI processes, normalises everything they emit
into one event model, keeps the transcript, and serves it over pinned TLS on
a WireGuard interface; the phone streams that, replies, sends images, and
imports conversations the machine already has.

`AGENTS.md` is the working guide -- what runs where, what has been measured,
and the faults that were expensive to find. `PLAN.md` is the design record.

History before this point was squashed away. It was a personal project's
running commentary and carried a name and a couple of machine paths that
have no business in a public repository; the tree is what mattered and the
tree is here.

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

@@ -0,0 +1,53 @@
+package com.example.aiapp
+
+import androidx.compose.foundation.Canvas
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.StrokeCap
+import androidx.compose.ui.unit.dp
+
+/**
+ * A chevron, pointing up or down.
+ *
+ * Drawn rather than set in a font: a chevron from an icon font is one of the glyphs a system font
+ * may simply not have, and the reader who gets an empty box instead is never the one who wrote it.
+ *
+ * One composable for both directions rather than two that differ by a minus sign -- the pair would
+ * drift, and the drift would be a bug in exactly one direction.
+ *
+ * It draws no label of its own, so every caller owes it a `contentDescription`: this is the whole
+ * of what assistive technology has to go on, and it is also the answer to "what was that arrow for"
+ * six months from now.
+ */
+@Composable
+fun Chevron(
+    pointingUp: Boolean,
+    modifier: Modifier = Modifier,
+    colour: Color = MaterialTheme.colorScheme.onSurfaceVariant,
+) {
+    Canvas(modifier.width(20.dp).height(10.dp)) {
+        val inset = 2.dp.toPx()
+        val point = if (pointingUp) inset else size.height - inset
+        val ends = if (pointingUp) size.height - inset else inset
+        val stroke = 2.dp.toPx()
+        drawLine(
+            colour,
+            Offset(inset, ends),
+            Offset(size.width / 2, point),
+            strokeWidth = stroke,
+            cap = StrokeCap.Round,
+        )
+        drawLine(
+            colour,
+            Offset(size.width / 2, point),
+            Offset(size.width - inset, ends),
+            strokeWidth = stroke,
+            cap = StrokeCap.Round,
+        )
+    }
+}