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/save-to-corpus.php

@@ -35,6 +35,13 @@ $tags       = json_encode(
     JSON_UNESCAPED_UNICODE
 );
 
+$rawSourceDocIds = $input['source_doc_ids'] ?? null;
+$sourceDocIdArr  = is_array($rawSourceDocIds)
+    ? $rawSourceDocIds
+    : (is_string($rawSourceDocIds) ? array_filter(array_map('trim', explode(',', $rawSourceDocIds))) : []);
+$firstSourceDocId = (int)(reset($sourceDocIdArr) ?: 0);
+$sourceUrl = $firstSourceDocId > 0 ? "corpus-doc:{$firstSourceDocId}" : null;
+
 if ($title === '') {
     dbnToolsError('title is required.', 400, 'bad_request');
 }
@@ -71,10 +78,10 @@ $wordCount = str_word_count($content);
 $ins = $db->prepare("
     INSERT INTO client_documents
       (client_id, corpus_id, title, source_type, content, category,
-       tags, import_method, source_tool, word_count, status)
-    VALUES (?, ?, ?, 'text', ?, 'tool-output', ?, 'tool_output', ?, ?, 'pending')
+       tags, import_method, source_tool, source_url, word_count, status)
+    VALUES (?, ?, ?, 'text', ?, 'tool-output', ?, 'tool_output', ?, ?, ?, 'pending')
 ");
-$ins->execute([$clientId, $corpusId, $title, $content, $tags, $sourceTool, $wordCount]);
+$ins->execute([$clientId, $corpusId, $title, $content, $tags, $sourceTool, $sourceUrl, $wordCount]);
 $docId = (int)$db->lastInsertId();
 
 try {