feat(app): add Electron desktop UI and evolve memory/retrieval layer

Introduce an Electron app with session browser, memory list, and usage
  views (vanilla JS + Vue scaffolding). On the data layer: add content_type
  and is_meta to messages for transcript control-plane filtering, introduce
  FTS5-backed memory recall with safe tokenization, support memory archival
  via forget() through the renamed --attune runtime, and expose anchors on
  memory records.

app/renderer/src/views/MemoryDetail.vue

@@ -0,0 +1,8 @@
+<script setup>
+defineOptions({ name: 'MemoryDetail' });
+defineProps({ id: String });
+</script>
+
+<template>
+  <div class="view-placeholder">MemoryDetail view for {{ id }} (TODO)</div>
+</template>