fix(web): 下载模块上移; 修复按钮遮挡版本文字与 APK 为空

- Landing: 下载模块移到 hero 之后 (特色/统计之前)
- 按钮 display:inline-block + width:auto + margin-bottom, 不再全宽压住版本文字
- android-build.yml: 配置中心 key 改用后缀匹配 (r2/CF_API_TOKEN),
  此前按精确名 CF_API_TOKEN 匹配导致 fetch 步骤报缺密钥 → android 构建从未跑,
  桶里没有任何 widget/ 对象, APK 下载 404/为空

.gitea/workflows/android-build.yml

@@ -145,6 +145,10 @@ jobs:
               "CFG_PROJECT_R2": ("CF_API_TOKEN", "CF_R2_PUBLIC_URL"),
           }
           wanted = {}
+          # 兼容 key 带分组前缀 (如 CommonExternalService 下是 r2/CF_API_TOKEN)
+          def match(cfg_key, token):
+              return cfg_key == token or cfg_key.rsplit("/", 1)[-1] == token
+
           for pid_env, keys in wanted_keys.items():
               pid = os.environ[pid_env]
               req = urllib.request.Request(f"{url}/api/projects/{pid}/configs")
@@ -153,8 +157,10 @@ jobs:
               with urllib.request.urlopen(req, timeout=20) as r:
                   data = json.load(r).get("data", [])
               for cfg in data:
-                  if cfg.get("key") in keys:
-                      wanted[cfg["key"]] = cfg.get("value", "")
+                  cfg_key = cfg.get("key", "")
+                  for wanted_key in keys:
+                      if match(cfg_key, wanted_key):
+                          wanted[wanted_key] = cfg.get("value", "")
           with open(os.environ["GITHUB_ENV"], "a", encoding="utf-8") as f:
               for k, v in wanted.items():
                   f.write(f"{k}={v}\n")