Remove redundant Wiki operation log

[lyingbug]

Summary

• remove the redundant Wiki Browser operation-log entry, feed UI, API client, and localized copy
• remove the dedicated /wiki/log route, repository/service/types, and storage writes
• keep wiki.content_changed summaries in the knowledge-base activity feed as the single activity surface
• remove the obsolete log page type and stale wiki_read_page("log") model guidance
• drop wiki_log_entries and legacy log-type pages through PostgreSQL and SQLite migrations

Why

The Wiki operation log duplicated the knowledge-base Activity view and was not used by Wiki retrieval. The model prompt still treated log as a special page even though the dedicated event table was never exposed through wiki_read_page, leaving a stale retrieval contract.

Impact

Wiki mutations remain visible through the knowledge-base Activity view. Applying the migration permanently removes existing dedicated Wiki log rows; rollback recreates only the empty schema and cannot restore deleted rows.

Validation

• npm run build
• go test ./internal/application/service ./internal/application/repository ./internal/handler ./internal/router ./internal/agent/tools ./internal/types
• SQLite init plus removal migration executed in memory
• Swagger documentation regenerated with make docs
• git diff --check

Known repository baselines remain outside this change: frontend type-check errors in sessionSidebarBuckets.ts, AgentEditorModal.vue, and SystemSettings.vue; full internal tests also retain existing Feishu logging and Notion/docparser SSRF fixture failures.