feat(settings): Jira config UI — admin config tab + per-user token in Profile

- backend: add parent_ticket field to JiraConfigOut/JiraConfigUpdate/_JIRA_KEYS
- backend: add get_jira_parent_ticket() helper in jira_service; use it in auto_create_test_issue() to set issue parent
- frontend/api: add jira_token_set to UserMeOut, jira_api_token to UserPreferencesUpdate, and full JiraConfigOut/Update types with getJiraConfig/updateJiraConfig/testJiraConnection functions
- frontend: expand ProfileSection with Jira API token password field (show/hide), token status badge, and account-id field
- frontend: add JiraConfigSection component (admin): enabled toggle, URL, project key, parent ticket, save + test connection
- frontend: add Jira tab (admin-only) with Link2 icon in SettingsPage sidebar

backend/app/services/jira_service.py

@@ -86,6 +86,11 @@ def is_jira_enabled(db: Session) -> bool:
     return settings.JIRA_ENABLED
 
 
+def get_jira_parent_ticket(db: Session) -> Optional[str]:
+    """Return the configured parent ticket key, or None if not set."""
+    return _read_system_config(db, "jira.parent_ticket") or None
+
+
 def upsert_jira_config(db: Session, key: str, value: str) -> None:
     """Persist a Jira config key-value pair."""
     from app.models.system_config import SystemConfig
@@ -327,6 +332,10 @@ def auto_create_test_issue(
             "labels": ["aegis", "security-test", mitre_id.replace(".", "-")],
         }
 
+        parent_ticket = get_jira_parent_ticket(db)
+        if parent_ticket:
+            fields["parent"] = {"key": parent_ticket}
+
         result = jira.issue_create(fields=fields)
         issue_key = result["key"]
         issue_id = result.get("id", "")