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/js/state.js

@@ -0,0 +1,34 @@
+// App state -- single source of truth for the renderer process.
+// Loaded collections (memories, sessions, projects) start empty and are
+// populated from the DB at boot.
+
+export const state = {
+  memories: [],
+  sessions: [],
+  projects: [],
+  route: 'memory',
+  view: 'active',          // 'active' | 'archived'
+  mode: 'list',            // 'list' | 'detail'
+  detailId: null,
+  subagentId: null,
+  subagentDescription: null,
+  pendingFocusUuid: null,
+  query: '',
+  projectFilter: 'all',
+  projectSearch: '',
+  sortDesc: true,
+  includeMessageBodies: false,
+  cursorId: null,
+  selection: new Set(),
+  showSource: false,
+  lastArchiveSnapshot: null,
+  undoTimer: null,
+  undoExpires: 0
+};
+
+// Platform detection
+export const IS_MAC = /Mac|iPhone|iPad/.test(navigator.platform);
+
+// SVG icon constants
+export const FOLDER_SVG = `<svg viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.4" stroke-linejoin="round"><path d="M2.5 4h4l1.5 1.5h5.5v7a1 1 0 0 1-1 1h-10a1 1 0 0 1-1-1v-8z"/></svg>`;
+export const FILE_SVG = `<svg viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.4" stroke-linejoin="round" stroke-linecap="round"><path d="M3.5 2h6l3 3v9a1 1 0 0 1-1 1h-8a1 1 0 0 1-1-1V3a1 1 0 0 1 1-1z"/><path d="M9.5 2v3h3"/></svg>`;