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/barnevernet.php

@@ -122,7 +122,13 @@ try {
         }
     }
 
-    $result = (new DbnBvjAnalyzerAgent())->run(
+    $personaSlug = (isset($input['profile']) && is_string($input['profile']) && trim($input['profile']) !== '')
+        ? trim($input['profile'])
+        : null;
+
+    $result = (new DbnBvjAnalyzerAgent())
+        ->withPersona($personaSlug)
+        ->run(
         $uploadedFiles,
         $advocateRole,
         $engine,