feat(jira+tests): 5 improvements from review

1. Jira status → In Progress on Start Execution
   - push_test_event calls set_issue_status("In Progress") when
     new_state == "red_executing" (non-fatal, separate try/except)

2. Jira assignee set on Start Execution
   - assign_issue() called with actor.jira_account_id when operator
     clicks Start (non-fatal)

3. Standalone tests parent ticket (OFS-20798)
   - New jira.parent_ticket_standalone config key
   - get_jira_parent_ticket_standalone() falls back to parent_ticket
   - auto_create_test_issue uses standalone parent for non-campaign tests
   - Exposed in /system/jira-config GET+PATCH and SettingsPage UI

4. Tests table: Created + Updated columns
   - Add Created column (created_at), fix Updated to show updated_at
   - Both use UTC-aware date parsing (append Z if no tz suffix)
   - updated_at added to Test TypeScript interface

5. Sortable columns in tests table
   - All 7 columns sortable: Name, Technique, State, Current Team,
     Platform, Created, Updated
   - Click to sort asc, click again to reverse; ChevronUp/Down indicator
   - Default sort: Created desc (newest first)

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

backend/app/routers/system.py

@@ -211,6 +211,7 @@ class JiraConfigOut(BaseModel):
     url: str
     project_key: str
     parent_ticket: str
+    parent_ticket_standalone: str  # parent for tests not in a campaign
     # Credentials are never returned
 
 
@@ -219,6 +220,7 @@ class JiraConfigUpdate(BaseModel):
     url: Optional[str] = None
     project_key: Optional[str] = None
     parent_ticket: Optional[str] = None
+    parent_ticket_standalone: Optional[str] = None
 
 
 _JIRA_KEYS = {
@@ -226,6 +228,7 @@ _JIRA_KEYS = {
     "url": "jira.url",
     "project_key": "jira.project_key",
     "parent_ticket": "jira.parent_ticket",
+    "parent_ticket_standalone": "jira.parent_ticket_standalone",
 }
 
 
@@ -238,13 +241,17 @@ def get_jira_config(
 
     **Requires** the ``admin`` role. Credentials are never returned.
     """
-    from app.services.jira_service import get_jira_url, get_jira_project_key, is_jira_enabled, get_jira_parent_ticket
+    from app.services.jira_service import (
+        get_jira_url, get_jira_project_key, is_jira_enabled,
+        get_jira_parent_ticket, get_jira_parent_ticket_standalone,
+    )
 
     return JiraConfigOut(
         enabled=is_jira_enabled(db),
         url=get_jira_url(db) or "",
         project_key=get_jira_project_key(db) or "",
         parent_ticket=get_jira_parent_ticket(db) or "",
+        parent_ticket_standalone=get_jira_parent_ticket_standalone(db) or "",
     )
 
 
@@ -259,7 +266,8 @@ def update_jira_config(
     **Requires** the ``admin`` role. Only provided fields are updated.
     """
     from app.services.jira_service import (
-        upsert_jira_config, get_jira_url, get_jira_project_key, is_jira_enabled, get_jira_parent_ticket,
+        upsert_jira_config, get_jira_url, get_jira_project_key, is_jira_enabled,
+        get_jira_parent_ticket, get_jira_parent_ticket_standalone,
     )
 
     update_data = payload.model_dump(exclude_unset=True)
@@ -274,6 +282,7 @@ def update_jira_config(
         url=get_jira_url(db) or "",
         project_key=get_jira_project_key(db) or "",
         parent_ticket=get_jira_parent_ticket(db) or "",
+        parent_ticket_standalone=get_jira_parent_ticket_standalone(db) or "",
     )