docs: correct WSProxy→App Proxy rename inaccuracies and recapture resource group screenshots

[ironAiken2]

While reviewing PR #7442 (docs: rename WSProxy to App Proxy across the manual), several factual inaccuracies were found and corrected. This is a follow-up correction PR stacked on top of #7442.

Corrections

1. overview.md (Local/Web wsproxy) — The rename PR incorrectly annotated this section as the component surfaced as App Proxy in the UI. In fact this describes the WebUI client-side proxy (src/wsproxy/, config.toml wsproxy.proxyURL), which is a different layer from the renamed server-side App Proxy. Reverted overview.md (en/ko/ja/th) to main.

2. TERMINOLOGY.md — Falsely claimed an internal wsproxy binary/daemon still exists. Verified against the core repo: there is no standalone wsproxy daemon. v1 = Manager-embedded stream proxy; v2 = separate App Proxy Coordinator + Worker service family. wsproxy survives only as internal identifiers (DB columns scaling_groups.wsproxy_addr/wsproxy_api_token, API route /scaling-groups/{sg}/wsproxy-version, constant WSPROXY_V1_VERSION). Corrected the description, reversed the authoring guidance, and fixed the mapping-table row.

3. admin_menu.md / trouble_shooting.md (en/ko/ja/th) — Removed the (formerly WSProxy) parenthetical across the manual and trimmed the v1/v2 fallback sentence in the App Proxy Server Address field description.

4. Screenshots — Recaptured modify_resource_group.png and create_resource_group.png in all 4 languages; the old captures still showed the WSProxy label.

JIRA Issue: FR-2916