M2 search: Postgres FTS backend + top search bar + results

- Migration 0005: generated tsvector column (title A + body B) + GIN index on
  notes; GET /api/notes/search?q= (websearch_to_tsquery, ts_rank, ACL-scoped,
  excludes trash), labels merged into results.
- Persistent AppShell layout (parent route + <RouterView> children) so the new
  top search box keeps focus across board/search/label navigation.
- SearchView (debounced live search from the shell → /search?q=, results masonry,
  no-match empty state); BoardView/SearchView render inside the shared shell.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

frontend/src/views/SearchView.vue

@@ -0,0 +1,67 @@
+<script setup lang="ts">
+import { computed, ref, watch } from "vue";
+import { useRoute } from "vue-router";
+import { api } from "../api/client";
+import type { Note } from "../stores/notes";
+import NoteCard from "../components/NoteCard.vue";
+import NoteEditor from "../components/NoteEditor.vue";
+
+const route = useRoute();
+
+const results = ref<Note[]>([]);
+const loading = ref(false);
+const editing = ref<Note | null>(null);
+
+const query = computed(() => (typeof route.query.q === "string" ? route.query.q : ""));
+
+async function run() {
+  const q = query.value.trim();
+  if (!q) {
+    results.value = [];
+    return;
+  }
+  loading.value = true;
+  try {
+    const res = await api.get<{ notes: Note[] }>(`/api/notes/search?q=${encodeURIComponent(q)}`);
+    results.value = res.notes;
+  } finally {
+    loading.value = false;
+  }
+}
+
+watch(query, run, { immediate: true });
+
+function openEditor(n: Note) {
+  editing.value = n;
+}
+async function closeEditor() {
+  editing.value = null;
+  await run(); // reflect any edits made from a result
+}
+</script>
+
+<template>
+  <div class="mx-auto w-full max-w-6xl px-4 py-6">
+    <p class="mb-4 text-sm text-neutral-500 dark:text-neutral-400">
+      <template v-if="query"
+        >Results for <span class="font-semibold text-neutral-800 dark:text-neutral-200">{{ query }}</span></template
+      >
+      <template v-else>Type in the search box to find your notes.</template>
+    </p>
+
+    <div v-if="loading" class="py-20 text-center text-sm text-neutral-400">Searching…</div>
+
+    <div v-else-if="query && results.length === 0" class="py-20 text-center">
+      <h2 class="text-lg font-semibold text-neutral-700 dark:text-neutral-200">No matches</h2>
+      <p class="mt-1 text-sm text-neutral-400">Nothing found for "{{ query }}".</p>
+    </div>
+
+    <div v-else class="columns-1 gap-4 sm:columns-2 lg:columns-3 xl:columns-4">
+      <NoteCard v-for="n in results" :key="n.id" :note="n" @open="openEditor" />
+    </div>
+  </div>
+
+  <template v-if="editing">
+    <NoteEditor :note="editing" @close="closeEditor" />
+  </template>
+</template>