Add remote routing URL support (#6168)

* Add remote routing URL support

* Harden remote routing refresh

* fix(sub): harden remote routing fetch and accept Mihomo src rule flag

Remote routing bytes reach the YAML/JSON parsers from goroutines that run
outside Gin's recovery, so a parser panic on crafted input would take down
the whole panel. Contain it in fetch() (a panic now degrades to a failed
refresh that keeps the last-good value and releases the in-flight slot)
and start the refresh, cache-load and startup-warm goroutines through
common.GoRecover like the other background workers.

The route-graph validator only skipped a trailing no-resolve flag, so a
valid Mihomo rule like IP-CIDR,x,DIRECT,no-resolve,src was rejected as an
unknown target; skip both option flags.

Also deduplicate the HTTPS-source classification into
common.ParseRemoteRoutingURL so the save-time validator and the resolver
can never drift (internal/sub imports internal/web/service, so the copy
existed only to avoid the import cycle), move the test-only
mergeRemoteClashRulesYAML helper into the test file, and trim oversized
comment blocks.

---------

Co-authored-by: Duxxie <yelloduxx@users.noreply.github.com>
Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

internal/web/translation/zh-TW.json

@@ -1158,17 +1158,17 @@
       "subEnableRouting": "啟用路由",
       "subEnableRoutingDesc": "在 VPN 用戶端中啟用路由的全域設定。（僅限 Happ）",
       "subRoutingRules": "路由規則",
-      "subRoutingRulesDesc": "VPN 用戶端的全域路由規則。（僅限 Happ）",
+      "subRoutingRulesDesc": "貼上現成的 happ:// 深層連結或一個固定 HTTPS URL。面板會在背景更新遠端規則並保留最後一個有效值，因此訂閱請求不需等待遠端來源。（僅限 Happ）",
       "subHideSettings": "隱藏伺服器設定",
       "subHideSettingsDesc": "在 VPN 用戶端中隱藏查看和編輯伺服器配置的功能。（僅限 Happ）",
       "subIncyEnableRouting": "啟用路由",
       "subIncyEnableRoutingDesc": "為 Incy 用戶端將路由設定檔注入訂閱內容中。（僅限 Incy）",
       "subIncyRoutingRules": "路由規則",
-      "subIncyRoutingRulesDesc": "加入訂閱內容的 Incy 路由深層連結，例如 incy://routing/onadd/<base64>。（僅限 Incy）",
+      "subIncyRoutingRulesDesc": "貼上現成的 incy:// 深層連結或指向 JSON 的固定 HTTPS URL。Incy 會建立 autorouting 設定並自動更新。（僅限 Incy）",
       "subClashEnableRouting": "啟用路由",
       "subClashEnableRoutingDesc": "在產生的 YAML 訂閱中包含 Clash/Mihomo 全域路由規則。",
       "subClashRoutingRules": "全域路由規則",
-      "subClashRoutingRulesDesc": "加入到每個 YAML 訂閱開頭、MATCH,PROXY 之前的 Clash/Mihomo 規則。",
+      "subClashRoutingRulesDesc": "貼上規則/YAML 或一個固定 HTTPS URL。面板會在背景更新，只匯入代理群組、規則提供者與規則，並保留面板產生的 VPN 節點及最後一個有效值。",
       "subListen": "監聽 IP",
       "subListenDesc": "訂閱服務監聽的 IP 地址（留空表示監聽所有 IP）",
       "subPort": "監聽埠",