chore(branding): remove leftover upstream theme identifiers

The theme was renamed Zibll/子比 → AKSRT → Jio, but upstream branding
survived the sweeps in CSS classes, the SVG sprite prefix, a persisted
widget field ID, JS events, admin Vue class names, test infrastructure
and docblocks.

Renames:
- zib-widget / zib-widget-wrap / zib-slider → jio-widget-box /
  jio-widget-box-wrap / jio-slider-box (jio-widget is taken by the modern
  widget shell, jio-box-* by the card primitives)
- zib-partners-scroll + zps-* → jio-partners-scroll + jps-*
- zib-combo-info-card + zci-* → jio-combo-info-card + jci-*
- zibsvg- → jiosvg-, including the exported picker helpers and the
  fa-zibsvg- family-prefix guard
- zibpay_type → pay_type; the dual-read fallback in PostQuery collapses
  to a single key
- [zibajax="submit"] dropped (no PHP emitter); zib_ajax.success →
  jio_ajax.success
- aks-* admin Vue classes → jio-*
- zib_palette() → palette()

User-facing vendor traces are gone: the floating "more" button default no
longer ships a zibll.com link or 子比主题 marketing copy, the notice
widget ships no preset promo entries, and the four 官网教程 links are
removed from the post-list admin schema.

Test infrastructure renamed to neutral names (docker-compose.reference.yml,
Caddyfile, article-baseline.json, modern-widgets-contract.test.cjs) with
their DB/volume/env/slug identifiers following.

Kept intentionally, documented in tests/fixtures/README.md: the golden
fixture reference fingerprint (a SHA-256 record of an external directory,
read by validate-widget-golden / generate-widget-golden-fixture /
audit-widget-system), the doesNotMatch guards that prove the old tokens are
gone, and the reference theme's own meta key in the visual fixtures.

No backward-compat or data migration: saved widget configs holding old
icon keys or the old field ID silently lose them, per the project's
rewrite-over-compatibility rule.

Verified: 132/132 node contract tests, php tests/widget-system/run.php
(146 assertions), audit-admin-contracts, audit-psr4-paths and
validate-widget-golden all green; tracked bundles regenerated and in sync.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/visual/article-visual-matrix-v1.json

@@ -1,5 +1,5 @@
 {
-  "schema": "jio.zibll-article-visual-matrix.v1",
+  "schema": "jio.article-visual-matrix.v1",
   "reference": "https://localhost:9443",
   "candidate": "https://localhost",
   "fixture": "/visual-fixtures/article-fixtures.php",
@@ -19,11 +19,11 @@
   "routes": [
     { "id": "home", "path": "/", "states": ["default", "hover", "loading", "error"] },
     { "id": "archive", "path": "/?post_type=post", "states": ["default", "numbered", "load-more", "infinite", "no-more"] },
-    { "id": "category", "path": "/category/zibll-article-fixture/", "states": ["default", "empty"] },
-    { "id": "tag", "path": "/tag/zibll-visual-tag/", "states": ["default", "empty"] },
+    { "id": "category", "path": "/category/article-fixture/", "states": ["default", "empty"] },
+    { "id": "tag", "path": "/tag/visual-tag/", "states": ["default", "empty"] },
     { "id": "search", "path": "/?s=视觉", "states": ["default", "empty"] },
-    { "id": "author-a", "path": "/author/zibll_article_v1_author_a/", "states": ["default", "numbered", "load-more"] },
-    { "id": "single-related", "path": "/zibll_article_v1_featured/", "states": ["img", "list", "text"] }
+    { "id": "author-a", "path": "/author/article_v1_author_a/", "states": ["default", "numbered", "load-more"] },
+    { "id": "single-related", "path": "/article_v1_featured/", "states": ["img", "list", "text"] }
   ],
   "postScenarios": ["featured", "no-image", "multi", "external", "slides", "video", "paid", "vip", "first-image"],
   "capture": {