docs: refresh docs and screenshots, drop em dashes, add scripts/screenshots.sh

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/cli.md

@@ -150,7 +150,7 @@ guara report s.json report.html --case 2026-001 --examiner "Name" --hash-source
 
 Includes case identification, source, partitions, summary, hashes, the audit trail status and the list of files. `--hash-source` adds the hash of the whole source. The format follows the extension: `report.pdf` writes an A4 PDF (standard fonts, nothing external), anything else writes HTML.
 
-## `update` — updating
+## `update`: updating
 
 ```bash
 guara update           # check for a new version