Unified search normalization across InternalLinkPicker and GlobalSearch:
1. GlobalSearch.svelte: multi-variant search (same as InternalLinkPicker)
- expandKeyboardVariants() for RU/EN layout swap
- Parallel Search queries with dedup by type+nodeId+targetId+title
- 180ms debounce preserved
2. Backend: fix LOWER() in SQL for links/actions
- Replace LOWER(column) LIKE with lowercased columns (title_lower, url_lower, etc.)
- Migration 020: add lowercased columns + indexes for links and actions
- BackfillLinksLower() + BackfillActionsLower() in storage.go
- Update INSERT in bindings_links.go and action.go to populate lowercased columns
3. FTS5 search: Unicode case-insensitive
- Index lowercased title/content/tags in search_index
- sanitizeFTS() now lowercases query before MATCH
- RebuildFTS() called after migrations
4. Case-insensitive search for nodes (already done in previous commit, verified):
- title_lower column with Go strings.ToLower
- Search() queries title_lower with lowercased query
All test suites PASS, full build OK.
mirivlad