feat(sub): add per-client subscription HWID limits (#5802)

* feat(sub): add per-client subscription HWID limits

* fix(sub): address HWID review on shared subId and bulk create

* fix(sub): store HWID devices by sub_id and drop anchor client workaround

* fix(sub): restore UA auto-detect and HTML page routing in subs()

The cherry-pick of the HWID gate onto main's refactored SUBController
had dropped main's UA-based format auto-detection and sub-page handling
from subs(). Restore those branches, slotting enforceHwid after the
HTML page and before format detection so the gate only applies to
machine-readable subscription bodies.

Also adapt tests to main's options-struct constructor and to the
ClientService.Update signature extended with limitHwid.

* fix(frontend): drop axios from HttpUtil.delete

The bulk-delete rework's committed version still referenced axios,
which this file no longer imports, breaking typecheck in CI. Use the
httpRequest wrapper like the other verbs.

---------

Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

internal/database/migrate_data.go

@@ -48,6 +48,7 @@ func migrationModels() []any {
 		&model.InboundClientIps{},
 		&model.ClientRecord{},
 		&model.ClientInbound{},
+		&model.ClientHwid{},
 		&model.ClientExternalLink{},
 		&model.ClientGroup{},
 		&model.InboundFallback{},