feat(phase-36): automatic Tempo time tracking via workflow buttons + fix campaign test management

- Add red_started_at/blue_started_at timing fields to Test model with Alembic migration

- Modify workflow transitions to auto-create integrity-hashed worklogs: Start Execution records red_started_at, Submit to Blue Team stops Red timer and creates worklog then starts Blue timer, Submit for Review stops Blue timer and creates worklog

- Auto-sync worklogs to Tempo when test has a Jira link

- Add LiveTimer component showing real-time elapsed counter during active phases

- Clear timing fields on test reopen

- Fix campaign test management: replace broken navigate-to-tests flow with AddTestToCampaignModal that lets users search and add existing tests directly from the campaign detail page

backend/app/models/test.py

@@ -49,6 +49,10 @@ class Test(Base):
     blue_validation_status = Column(String, nullable=True)  # pending / approved / rejected
     blue_validation_notes = Column(Text, nullable=True)
 
+    # ── Phase timing fields (for automatic Tempo worklogs) ──────────
+    red_started_at = Column(DateTime, nullable=True)
+    blue_started_at = Column(DateTime, nullable=True)
+
     # ── Remediation fields ───────────────────────────────────────────
     remediation_steps = Column(Text, nullable=True)
     remediation_status = Column(String, nullable=True)  # pending / in_progress / completed / not_applicable