feat: complete person identity matching system with fuzzy detection, revert, and manual link

Implements the full identity matching engine: email matching (HIGH confidence),
fuzzy name matching with Levenshtein distance (MEDIUM confidence, upgradable to
HIGH with DOB tiebreaker), manual link/unlink, revert confirmed matches, and
automatic detection via PersonObserver. Includes 33 comprehensive tests, frontend
integration with confirm/dismiss/unlink UI, and match indicators in the persons list.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/Enums/IdentityMatchStatus.php

@@ -9,4 +9,20 @@ enum IdentityMatchStatus: string
     case PENDING = 'pending';
     case CONFIRMED = 'confirmed';
     case DISMISSED = 'dismissed';
+    case REVERTED = 'reverted';
+
+    public function isTerminal(): bool
+    {
+        return in_array($this, [self::DISMISSED, self::REVERTED]);
+    }
+
+    public function label(): string
+    {
+        return match ($this) {
+            self::PENDING => 'In afwachting',
+            self::CONFIRMED => 'Bevestigd',
+            self::DISMISSED => 'Afgewezen',
+            self::REVERTED => 'Ontkoppeld',
+        };
+    }
 }