fix(tempo,jira,tests,ui): fix 4 pending issues

- tempo: remove unsupported `workType` kwarg from create_worklog call;
  tempoapiclient v4 does not accept it → was causing every Tempo sync to fail
- tests: set created_at=datetime.utcnow() explicitly on test creation (both
  create_test and create_test_from_template) since the DB column has no
  server default, causing 'Created —' in the UI
- jira: remove duplicate Proof of Concept section from ticket description body;
  PoC already lives in customfield_10309, no need to repeat it in description
- ui: add TestPhaseTimeline component (read-only) showing RT execution time,
  blue queue time, blue evaluation time and lead validation timestamps derived
  from test phase timestamps; placed above WorklogTimeline in test detail page

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

backend/app/services/test_crud_service.py

@@ -5,6 +5,7 @@ The router is responsible for HTTP concerns, auth, audit logging, and commit.
 """
 
 import uuid
+from datetime import datetime
 from typing import Any
 
 from sqlalchemy.orm import Session, joinedload
@@ -78,6 +79,7 @@ def create_test(
         technique_id=technique_id,
         created_by=creator_id,
         state=TestState.draft,
+        created_at=datetime.utcnow(),  # explicit — DB column has no server default
         **fields,
     )
     db.add(test)
@@ -127,6 +129,7 @@ def create_test_from_template(
         remediation_steps=template.suggested_remediation,
         created_by=creator_id,
         state=TestState.draft,
+        created_at=datetime.utcnow(),  # explicit — DB column has no server default
     )
     db.add(test)
     db.flush()