feat(clients): support setting HWID limit and MTProto ad-tag in bulk adjust (#6399)

* feat(clients): support setting HWID limit and MTProto ad-tag in bulk adjust

Add HWID device limit and Telegram MTProto sponsor channel (ad-tag)
support to the bulk client adjustment flow in both the panel API
and frontend ClientBulkAdjustModal.

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

* fix(clients): gate adTag to MTProto inbounds and avoid inbound rewrite for limitHwid

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

* fix(clients): stamp updated_at only on the clients a bulk adjust changed

The updated_at write was gated on hasInboundChanges, which accumulates
over the whole inbound instead of describing the client in hand. Once any
client in the settings array changed, every client after it was re-stamped
as well, so whether an untouched client kept its own updated_at depended on
its position in the array. That field feeds node-snapshot conflict
resolution, where a spurious bump lets a stale snapshot value win over the
stored record.

Track the change per client and fold it into the inbound-level flag where
the stamp is written, so the early return still skips a save whose settings
JSON would be unchanged.

Also condenses the BulkAdjust doc comment back to the two-line maximum.

* docs(api): regenerate the bulkAdjust reference for limitHwid and adTag

frontend/public/openapi.json was copied to docs/public/, but pnpm gen:api
was never re-run, so the API reference page's heading, anchor id and search
index still described bulkAdjust without limitHwid or adTag. docs-ci.yml
fires only on docs/**, and that path had been touched, so nothing flagged
the stale MDX.

The externalLinks hunks are the generator rewrapping lines main had left
stale, not a content change.

* fix(i18n): stop enumerating fields in the bulk-adjust empty-form message

bulkAdjustNothing listed the fields the form accepts, so it went stale
every time one was added: only en-US ever gained "flow", leaving the other
twelve locales describing days and traffic alone, and limitHwid and adTag
would have repeated that. Say that one field is required instead of naming
which, so the message cannot drift again.

internal/web/translation/zh-TW.json

@@ -846,7 +846,7 @@
       "bulkDeleteConfirmContent": "每個所選客戶端都會從關聯的入站中被移除，其流量紀錄也會被刪除。此操作無法復原。",
       "bulkAdjustTitle": "調整 {count} 個客戶端",
       "bulkAdjustHint": "正值延長，負值減少。具有無限期限或流量的客戶端將跳過該欄位。",
-      "bulkAdjustNothing": "套用前請設定天數或流量。",
+      "bulkAdjustNothing": "套用前請至少設定一項。",
       "addDays": "新增天數",
       "addTrafficGB": "新增流量 (GB)",
       "bulkFlow": "設定 flow",
@@ -912,7 +912,8 @@
       "renewMaxDesc": "自動續期最多可觸發的次數，達到後用戶端將自然到期。填 0 表示不限制。補齊多個錯過的週期時，每個週期消耗一次續期。",
       "renewOnDay": "按日期續期",
       "renewOnDayDesc": "每個自然月的這一天午夜（依面板時區）續期，而不是每 N 天續期一次。若當月沒有該日期，則在當月最後一天續期。填 0 保持按天間隔模式。",
-      "renewsUsed": "已用續期次數"
+      "renewsUsed": "已用續期次數",
+      "bulkAdTagHint": "輸入 32 位十六進位標籤以設定，或輸入 'none' 清除 MTProto 贊助頻道。"
     },
     "groups": {
       "name": "名稱",