Update views, API, and exports for new ArchiveResult output fields

Replace old `output` field with new fields across the codebase:
- output_str: Human-readable output summary
- output_json: Structured metadata (optional)
- output_files: Dict of output files with metadata
- output_size: Total size in bytes
- output_mimetypes: CSV of file mimetypes

Files updated:
- api/v1_core.py: Update MinimalArchiveResultSchema to expose new fields
- api/v1_core.py: Update ArchiveResultFilterSchema to search output_str
- cli/archivebox_extract.py: Use output_str in CLI output
- core/admin_archiveresults.py: Update admin fields, search, and fieldsets
- core/admin_archiveresults.py: Fix output_html variable name bug in output_summary
- misc/jsonl.py: Update archiveresult_to_jsonl() to include new fields
- plugins/extractor_utils.py: Update ExtractorResult helper class

The embed_path() method already uses output_files and output_str,
so snapshot detail page and template tags work correctly.

archivebox/misc/jsonl.py

@@ -174,16 +174,30 @@ def archiveresult_to_jsonl(result) -> Dict[str, Any]:
     """
     Convert an ArchiveResult model instance to a JSONL record.
     """
-    return {
+    record = {
         'type': TYPE_ARCHIVERESULT,
         'id': str(result.id),
         'snapshot_id': str(result.snapshot_id),
         'extractor': result.extractor,
         'status': result.status,
-        'output': result.output,
+        'output_str': result.output_str,
         'start_ts': result.start_ts.isoformat() if result.start_ts else None,
         'end_ts': result.end_ts.isoformat() if result.end_ts else None,
     }
+    # Include optional fields if set
+    if result.output_json:
+        record['output_json'] = result.output_json
+    if result.output_files:
+        record['output_files'] = result.output_files
+    if result.output_size:
+        record['output_size'] = result.output_size
+    if result.output_mimetypes:
+        record['output_mimetypes'] = result.output_mimetypes
+    if result.cmd:
+        record['cmd'] = result.cmd
+    if result.cmd_version:
+        record['cmd_version'] = result.cmd_version
+    return record
 
 
 def tag_to_jsonl(tag) -> Dict[str, Any]: