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>

frontend/src/pages/TestDetailPage.tsx

@@ -29,6 +29,7 @@ import ValidationModal from "../components/test-detail/ValidationModal";
 import ConfirmDialog from "../components/ConfirmDialog";
 import JiraLinkPanel from "../components/JiraLinkPanel";
 import WorklogTimeline from "../components/WorklogTimeline";
+import TestPhaseTimeline from "../components/TestPhaseTimeline";
 
 // ── Page Component ─────────────────────────────────────────────────
 
@@ -540,7 +541,10 @@ export default function TestDetailPage() {
           {/* Jira Integration */}
           <JiraLinkPanel entityType="test" entityId={testId!} />
 
-          {/* Time Tracking */}
+          {/* Phase Timeline (read-only, derived from test timestamps) */}
+          <TestPhaseTimeline test={test} />
+
+          {/* Time Tracking (manual worklogs) */}
           <WorklogTimeline entityType="test" entityId={testId!} />
         </div>
       </div>