feat(i18n-ko): desktop slice 2 — remaining settings/conversation/artifact/browser/mcp/plan-mode

[me2seeks]

Problem

Remaining Desktop domains still fall back to English in ko: conversation, artifacts, browser, MCP, plan mode, and the rest of settings-*.

Desired outcome

Add ko entries via UiCatalog<T> for:

• artifact-copy.ts, browser-copy.ts, conversation-copy.ts, external-session-import-copy.ts
• mcp-copy.ts, plan-mode-copy.ts
• settings-bot-copy.ts, settings-daily-review-copy.ts, settings-data-copy.ts, settings-health-copy.ts, settings-memory-copy.ts, settings-navigation-copy.ts, settings-projects-copy.ts, settings-provider-copy.ts, settings-shared-copy.ts, settings-subagents-copy.ts, settings-tasks-copy.ts, settings-test-result-copy.ts, settings-usage-copy.ts, settings-web-search-copy.ts

Follows #3853 coverage for zh-TW.

Alternatives or workarounds

Leave these domains in English.

Acceptance criteria

• All listed catalogs provide ko; no untranslated fallback where catalog exists
• Typecheck fails if a new key is added without ko entry (UiCatalog<T>)
• npm --workspace @maka/ui test / @maka/core related suites green
• Screenshots for representative surfaces (conversation, plan mode)

Parent: #3974