feat(tests): archive round history on reopen, stop pausing from setting Jira On Hold

- Reopening a test for rework (red or blue) now archives the round that's
  ending into a new test_round_history table before resetting the live
  fields — procedure/results/detection data is preserved instead of
  overwritten, and Phase Timeline renders every past round alongside the
  current one, so Blue Team keeps visibility into earlier Red attempts.
- Each archived round also posts a permanent Jira comment (push_round_archived)
  since Jira's custom fields only ever show the latest value once the next
  round resubmits — the comment thread is what preserves full history there.
- push_pause_event no longer transitions the Jira issue to "On Hold" — a
  timer pause is not a real Hold, and flipping Jira status for it was
  misleading. Only the explicit Hold action (push_hold_event) does that now.

backend/app/models/test.py

@@ -108,6 +108,10 @@ class Test(Base):
     # Assign blue_paused_seconds = Column(Integer, default=0)
     blue_paused_seconds = Column(Integer, default=0)
 
+    # ── Round tracking (bumped on each reopen-for-rework) ────────────
+    red_round_number = Column(Integer, nullable=False, default=1, server_default="1")
+    blue_round_number = Column(Integer, nullable=False, default=1, server_default="1")
+
     # ── Remediation fields ───────────────────────────────────────────
     remediation_steps = Column(Text, nullable=True)
     # Assign remediation_status = Column(String, nullable=True)  # pending / in_progress / completed ...
@@ -126,6 +130,10 @@ class Test(Base):
     technique = relationship("Technique", back_populates="tests")
     # Assign evidences = relationship("Evidence", back_populates="test")
     evidences = relationship("Evidence", back_populates="test")
+    round_history = relationship(
+        "TestRoundHistory", back_populates="test",
+        order_by="TestRoundHistory.round_number", cascade="all, delete-orphan",
+    )
     # Assign creator = relationship("User", foreign_keys=[created_by])
     creator = relationship("User", foreign_keys=[created_by])
     # Assign red_validator = relationship("User", foreign_keys=[red_validated_by])