feat(ai-sdk): close the 4 GT #3 recall gaps — backflow, cut, restart, spray-arm

Phase 1 complete. GT #3 recall 84% -> 100% (25/25 matched), no regression:
- HP2207 backflow / potable-water contamination (EN 1717) + measure M2209
  (Rueckflussverhinderer / Systemtrenner) — the only genuinely new hazard.
- HP2208 cut on sharp edges/screens (new sharp_edge tag from scharfe-Kante/Sieb).
- HP2209 unexpected restart during maintenance (dedicated dom_warewashing pattern;
  avoids flooding the log via the broad moving_part tag).
- Spray-arm contact now covered by the enclosure-re-scoped contact patterns.

Kistenhub 97.1% and Bremse pinned mappings unchanged; 0/28 hazards without a
measure. Completes the commercial-dishwasher (white-goods Phase 1) coverage.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ai-compliance-sdk/internal/iace/keyword_dictionary.go

@@ -107,6 +107,9 @@ func GetKeywordDictionary() []KeywordEntry {
 		// honest (generic hygiene; surfaced by the warewashing GT).
 		{Keywords: []string{"spuelarm", "spuelfeld", "wascharm", "spruehfeld"}, ExtraTags: []string{"rotating_part"}},
 		{Keywords: []string{"spuelkammer", "spueltuer", "geraetetuer", "haubentuer", "klapptuer"}, ExtraTags: []string{"access_door"}},
+		// Frischwasseranschluss an das Trinkwassernetz -> Rueckfluss/Ruecksaug-Risiko (EN 1717).
+		{Keywords: []string{"rueckfluss", "rueckflussverhinderer", "ruecksaug", "trinkwasser", "frischwasseranschluss", "systemtrenner"}, ExtraTags: []string{"backflow_risk"}},
+		{Keywords: []string{"scharfe kante", "scharfkant", "blechkante", "scharfe blechkante", "sieb", "siebe"}, ExtraTags: []string{"sharp_edge"}},
 		// Ghost-Closure (Emit-Seite): macht die 34 toten Required-Tags
 		// emittierbar, jeweils NUR via domaenenspezifische Keywords -> die 120
 		// Ghost-Patterns feuern wieder, aber nur fuer ihre echte Maschine (kein