feat(ext): verify cookies in-browser before uploading (1.0.7)

Pre-upload verify request: after capturing the live browser cookies,
hit a known authenticated endpoint with credentials:'include' from the
extension's background context. If the platform reports we're not
logged in, abort the upload so we don't overwrite FC-side credentials
with stale data.

- platforms.js: add `verify` config per cookie-auth platform
  - hentaifoundry: HEAD /?enterAgree=1 (mirrors gallery-dl's HF
    _init_site_filters; same 401 path the operator hit 2026-06-03)
  - patreon: GET /api/current_user (clean 401 when logged out)
  - subscribestar, deviantart: no stable auth endpoint, skip verify
- cookies.js: verifyCookiesForPlatform() returns {ok, status, reason}.
  ok=true/false/null tri-state — null = verify not configured, caller
  treats as "proceed".
- background.js EXPORT_COOKIES + EXPORT_ALL_COOKIES: verify gates the
  upload; failures bubble up with the platform's name + reason.
- popup.js: success message now appends "(verified ✓)" when applicable.
- manifest + package.json: 1.0.6 → 1.0.7.

extension/package.json

@@ -1,6 +1,6 @@
 {
   "name": "fabledcurator-extension",
-  "version": "1.0.6",
+  "version": "1.0.7",
   "private": true,
   "description": "Firefox extension for FabledCurator",
   "scripts": {