Integrate dbn-legal-agent-v2: upgrade all v1 refs + add Korrespond legal-check

- Replace dbn-legal-agent with dbn-legal-agent-v2 in bootstrap.php
  (dbnToolsRunLegalCheck), DeepResearchAgent.php (interpretSeed,
  expandQueries, synthesis fallback, deploy label), BvjAnalyzerAgent.php
  (check_model label) — 8 locations total
- Add dbn-legal-agent-v2 legal threshold check to KorrespondAgent:
  called after selfCheck() in both generate() and refine(); result
  surfaced as legal_check[] in the API response
- Render legal_check card in korrespond.js using existing bvj-red-flag
  styles; shows only when non-empty
- Add .korr-legal-check CSS block in tools.css

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

includes/bootstrap.php

@@ -863,7 +863,7 @@ function dbnToolsRunLegalCheck(string $brief, string $docType): array
     }
 
     $opts = [
-        'model'       => 'dbn-legal-agent',
+        'model'       => 'dbn-legal-agent-v2',
         'temperature' => 0.1,
         'max_tokens'  => 350,
         'timeout'     => 120,
@@ -895,7 +895,7 @@ function dbnToolsRunLegalCheck(string $brief, string $docType): array
         'legal_basis'  => dbnToolsExtractCheckLegalBasis($clean),
         'source_refs'  => [],
         'what_to_check'=> 'Verifiser med norsk familieretsadvokat',
-        'check_model'  => 'dbn-legal-agent',
+        'check_model'  => 'dbn-legal-agent-v2',
     ]];
 }