feat: Legal Tools v1 — multilingual landing, dashboard, SSO bridge

- Public landing page at / for unauthenticated users (EN/NO/UK/PL)
- Authenticated / shows Case Workbench dashboard with manifesto strip,
  stats, and launched-tool grid (Transcribe, Timeline, BVJ, Advocate,
  Deep Research, Corpus)
- Added includes/i18n.php with full 4-language translation layer
- Extended layout.php to Case Workbench shell with tool rail, lang switcher
- AI output language normalization extended to en/no/uk/pl in PHP agents
- SSO token validation in bootstrap.php / index.php (dobetternorge.no bridge)

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

includes/LegalTools.php

@@ -139,9 +139,12 @@ final class DbnLegalToolsService
             return [
                 'tool' => 'ask',
                 'language' => $language,
-                'answer' => $language === 'no'
-                    ? 'Jeg fant ikke nok kildestøtte i familie-rettskorpuset til å svare sikkert.'
-                    : 'I did not find enough source support in the family-law corpus to answer safely.',
+                'answer' => match (dbnToolsNormalizeUiLanguage($language)) {
+                    'no' => 'Jeg fant ikke nok kildestøtte i familierettskorpuset til å svare sikkert.',
+                    'uk' => 'Я не знайшов достатньої підтримки в корпусі сімейного права, щоб відповісти безпечно.',
+                    'pl' => 'Nie znalazłem wystarczającego wsparcia źródłowego w korpusie prawa rodzinnego, aby odpowiedzieć bezpiecznie.',
+                    default => 'I did not find enough source support in the family-law corpus to answer safely.',
+                },
                 'what_we_found' => $search['what_we_found'],
                 'evidence_trail' => [],
                 'what_remains_uncertain' => $search['what_remains_uncertain'],
@@ -160,7 +163,7 @@ final class DbnLegalToolsService
         $this->azure->requireChat();
 
         $context = $this->buildEvidenceContext($hits);
-        $locale = $language === 'no' ? 'Norwegian' : 'English';
+        $locale = dbnToolsLanguageName($language);
         $prompt = <<<PROMPT
 Question:
 {$question}
@@ -229,7 +232,7 @@ PROMPT;
         $text = $this->requirePasteText($text);
         $this->azure->requireChat();
 
-        $locale = $language === 'no' ? 'Norwegian' : 'English';
+        $locale = dbnToolsLanguageName($language);
         $prompt = <<<PROMPT
 Summarize this pasted case-preparation text in {$locale}. Do not invent missing facts.
 
@@ -296,7 +299,7 @@ PROMPT;
             $this->azure->requireChat();
         }
 
-        $locale = $language === 'no' ? 'Norwegian' : 'English';
+        $locale = dbnToolsLanguageName($language);
 
         $focusInstruction = match ($focus) {
             'deadlines' => "\nFocus specifically on: legal deadlines, filing dates, response windows, appeal periods, and statutory time limits. Deprioritise narrative events with no legal deadline significance.",
@@ -599,7 +602,7 @@ PROMPT;
 
     private function legalJsonSystemPrompt(string $language): string
     {
-        $locale = $language === 'no' ? 'Norwegian' : 'English';
+        $locale = dbnToolsLanguageName($language);
         return <<<PROMPT
 You are Do Better Norge Legal Tools in a source-grounded legal preparation workflow.
 Use the DBN legal guardrails: