feat(phase-11): implement Red/Blue business logic services (T-106, T-107, T-108)

T-106: Create test_workflow_service.py with state-machine transitions for the complete test lifecycle (draft -> red_executing -> blue_evaluating -> in_review -> validated/rejected), dual validation by Red/Blue leads, and reopen capability with field cleanup.

T-107: Update status_service.py to use detection_result from Blue Team instead of legacy result field, and differentiate between partial progress (some validated) vs all-in-progress states.

T-108: Create atomic_import_service.py that downloads the Atomic Red Team repo as a ZIP (avoiding API rate limits), parses all atomics YAML files, and creates idempotent TestTemplate records mapped to MITRE techniques.

Includes validation tests for all three tasks (19 checks total).

backend/alembic/versions/b001_add_new_test_states.py

@@ -0,0 +1,32 @@
+"""add_new_test_states
+
+Revision ID: b001add0test
+Revises: a1412d1ef337
+Create Date: 2026-02-09 10:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'b001add0test'
+down_revision: Union[str, Sequence[str], None] = 'a1412d1ef337'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add red_executing and blue_evaluating values to the teststate enum."""
+    op.execute("ALTER TYPE teststate ADD VALUE IF NOT EXISTS 'red_executing' AFTER 'draft'")
+    op.execute("ALTER TYPE teststate ADD VALUE IF NOT EXISTS 'blue_evaluating' AFTER 'red_executing'")
+
+
+def downgrade() -> None:
+    """Downgrade: removing enum values in PostgreSQL requires recreating the type.
+
+    This is intentionally left as a no-op because dropping enum values is
+    destructive and rarely needed in practice.
+    """
+    pass