redact: UX overhaul — engine simplification, credits, spinner, save-to-docs, badges

- Remove GPU/regex engine options; keep only azure_mini (1 credit) and azure_full (2 credits)
- Variable credit cost: engine-aware pre-check and charge in api/redact.php; PricingCatalog base = 1
- Fix ATTORNEY not preserved when keepOfficials=true: add to LLM prompt, generic-tag, pseudonym regexes
- Replace Azure credits hint with per-engine credit cost text (all 4 languages)
- Single-file upload only (was: up to 5); simplify status messages
- Clear previous redaction output and show pulsing spinner when a new run starts
- Add "Save to My Docs" button in redact output panel (corpus-save.js path)
- corpus-save.js: capture source_doc_ids from button dataset, pass in POST payload
- api/save-to-corpus.php: accept source_doc_ids, store first as source_url=corpus-doc:{id}
- doc-picker.js: show "✂ Redacted" badge for documents saved from the redact tool
- CSS: .redact-working spinner, doc-item__badge--redact pill styles

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

api/redact.php

@@ -5,8 +5,15 @@ require_once __DIR__ . '/../includes/LegalTools.php';
 
 dbnToolsRequireMethod('POST');
 dbnToolsRequireAuth();
-$ftUid = dbnToolsFreeTierCheck('redact');
+
+// Determine engine and its credit cost before the pre-flight credit check
 $input = dbnToolsJsonInput(400000);
+$_validEngines = ['azure_mini', 'azure_full'];
+$_engine       = in_array((string)($input['engine'] ?? ''), $_validEngines, true)
+    ? (string)$input['engine'] : 'azure_mini';
+$_engineCredits = $_engine === 'azure_full' ? 2 : 1;
+
+$ftUid = dbnToolsFreeTierCheckAmount('redact', $_engineCredits);
 
 dbnToolsWithChargedTelemetry('redact', '', $ftUid, function () use ($input): array {
     $text     = dbnToolsInjectDocContent($input, dbnToolsString($input, 'text', 128000, false));
@@ -17,7 +24,7 @@ dbnToolsWithChargedTelemetry('redact', '', $ftUid, function () use ($input): arr
     $region   = dbnToolsNormalizeRegion($input['region']   ?? 'nordic');
     $language = dbnToolsNormalizeLanguage($input['language'] ?? 'en');
 
-    $validEngines = ['azure_mini', 'azure_full', 'gpu', 'regex'];
+    $validEngines = ['azure_mini', 'azure_full'];
     $engine = in_array((string)($input['engine'] ?? ''), $validEngines, true)
         ? (string)$input['engine']
         : 'azure_mini';
@@ -67,4 +74,4 @@ dbnToolsWithChargedTelemetry('redact', '', $ftUid, function () use ($input): arr
         $text, $mode, $region, $language, $aliases,
         $engine, $outputFormat, $keepOfficials, $exemptNames, $redactTypes
     );
-});
+}, $_engineCredits);