Implement Tefter per SPEC.md: NV-style notes with server, sync, PWA, desktop

- frontend/: Svelte 4 + TS + Vite app — omnibar (search-and-create), ranked
  diacritic-insensitive filtering, CodeMirror 6 markdown editor with 400ms
  autosave, marked+DOMPurify preview with [[wiki-links]], tag filter, undo
  toast, light/dark, narrow-screen stacked layout, IndexedDB store, pull-then-
  push sync engine with conflict handling, versioned cache-first service
  worker + manifest (installable PWA)
- server/: tefterd — Go stdlib HTTP + modernc.org/sqlite, /api/v1 sync API
  (changes/batch/health/import), SHA-256 hashed bearer token, LWW-with-
  conflict-copies push rules, subcommands: init, token rotate, import
  simplenote, compact, backup (VACUUM INTO); embeds the frontend bundle
- desktop/: Wails v2 shell — single instance, hide-to-tray (fyne systray),
  global Ctrl+Shift+Space hotkey, quit-on-close flag
- Simplenote import (CLI + web upload), idempotent via source_id dedupe;
  verified against a real 242-note export
- Makefile (frontend/server/server-all/desktop/test), GitHub release workflow,
  README with systemd/Caddy/backup docs

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/public/manifest.webmanifest

@@ -0,0 +1,15 @@
+{
+  "name": "Tefter",
+  "short_name": "Tefter",
+  "description": "Self-hosted Notational Velocity style notes",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#1a1a1a",
+  "theme_color": "#2f6fde",
+  "icons": [
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-512-maskable.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" }
+  ]
+}