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/jira_service.py

@@ -219,9 +219,6 @@ def _build_test_description(test: Test, technique: Optional[Technique]) -> str:
         "h3. Description",
         test.description or "_No description provided._",
         "",
-        "h3. Proof of Concept",
-        f"{{code}}{test.procedure_text or 'N/A'}{{code}}",
-        "",
         f"*Tool:* {test.tool_used or 'N/A'}",
         "",
         "----",