desktop M10.3: frontend data-source adapter seam (repo interface + rest.ts)

Extract a typed repository interface (adapters/repo.ts) from the scattered
store/view -> api.* calls, backed by adapters/rest.ts (verbatim HTTP mapping)
and selected through adapters/index.ts. Every store and the notes-facing views
now depend on `repo`, never the HTTP client directly -- the seam the offline
local source (M10.5, over Tauri invoke) plugs into next.

Behavior-preserving for web: rest.ts maps each semantic method to the exact
endpoint the code called before; query-string and multipart building moved out
of the stores/views into rest.ts (the one place that knows the URL shape).
Client-side logic (reconcile/sort/optimistic reorder/toasts) stays in the
stores. GraphView + admin SettingsView keep direct api calls -- out of the
offline-core scope (M10.5 is board/editor/capture/search/filter/labels/
checklists/reminders).

Task 1992.

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

frontend/src/components/NoteEditor.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { computed, nextTick, onMounted, ref, watch } from "vue";
-import { api } from "../api/client";
+import { repo } from "../adapters";
 import { useNotesStore } from "../stores/notes";
 import { useConfigStore } from "../stores/config";
 import { useTitlesStore, type TitleEntry } from "../stores/titles";
@@ -206,8 +206,7 @@ async function loadBacklinks(): Promise<void> {
     return;
   }
   try {
-    const res = await api.get<{ backlinks: { id: string; title: string }[] }>(`/api/notes/${noteId.value}/backlinks`);
-    backlinks.value = res.backlinks;
+    backlinks.value = await repo.notes.backlinks(noteId.value);
   } catch {
     backlinks.value = [];
   }
@@ -264,8 +263,8 @@ function refreshLinkMatches() {
   const q = linkQuery.value.trim();
   linkTimer = setTimeout(async () => {
     try {
-      const res = await api.get<{ results: TitleEntry[] }>(`/api/notes/link-search?q=${encodeURIComponent(q)}`);
-      linkMatches.value = res.results.filter((r) => r.id !== noteId.value).slice(0, 8);
+      const results = await repo.notes.linkSearch(q);
+      linkMatches.value = results.filter((r) => r.id !== noteId.value).slice(0, 8);
     } catch {
       linkMatches.value = [];
     }