feat(tools): persona-driven multi-domain corpus + model routing

Generalize the family-locked legal tools into caveauAI persona profiles
(client 57 chat profiles, resolved in-process via the chat_profiles bridge).
Each tool accepts an optional `profile` slug that scopes the corpus package(s),
search method, system prompt and synthesis model; omitting it falls back to the
family-legal package so existing behaviour is unchanged.

- dbnToolsResolvePersona / dbnToolsListPersonas / dbnToolsBootChatProfiles in
  bootstrap.php; new api/personas.php + dbn.list_personas MCP tool.
- LegalTools search/ask/corpusContextForSummarize and the BvjAnalyzer /
  LegalAnalysis / translate paths take the persona's packages + prompt + model.
- Persona <select> on ask/search/summarize (populated from api/personas.php).

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

api/search.php

@@ -20,5 +20,8 @@ dbnToolsWithTelemetry('search', $language, function () use ($input, $language):
     $scope = in_array($input['corpus_scope'] ?? '', ['shared', 'private', 'both'], true)
         ? $input['corpus_scope']
         : 'both';
-    return (new DbnLegalToolsService())->search($query, $language, $limit, $temporalMode, $asOfDate, $scope);
+    $persona = (isset($input['profile']) && is_string($input['profile']) && trim($input['profile']) !== '')
+        ? trim($input['profile'])
+        : null;
+    return (new DbnLegalToolsService())->search($query, $language, $limit, $temporalMode, $asOfDate, $scope, $persona);
 });