fix: update migrated CN legacy links

[Foesa-yyx]

Summary

• Rewrites migrated CN docs that still pointed to legacy Online KTV, 1v1 Live CallAPI, IoT aPaaS, and Teleoperation API routes.
• Adds a report documenting the broken-link causes and why generated HTML API references were not migrated in this pass.

Fixed link families

• /api-ref/online-ktv/{android,ios}/ktvapi -> /zh-CN/solutions/online-ktv/ktv-scenario/reference/ktv-api
• /api-ref/one-to-one-live/{android,ios}/call-api -> /zh-CN/api-reference/private-room/{android,ios}
• /api-ref/iot-apaas/... -> migrated IoT aPaaS API reference pages
• /api-ref/teleoperation/iot/api/device -> /zh-CN/solutions/teleoperation/reference/device

Notes

Remaining RTC Web JS, RTSA C/Java, RTC Server SDK C++/Java broken API links are generated HTML API references in the legacy source. They are documented as requiring a separate generated-HTML migration lane and are intentionally excluded from this non-HTML mapping fix.

Verification

• rg -n "/api-ref/online-ktv|/api-ref/teleoperation|/api-ref/one-to-one-live|/api-ref/iot-apaas" content/docs/zh-CN returns no matches
• git diff --check
• bun run types:check