feat(1e): HC3 additive generic + op/assertion split (orchestrator owns the op)

- orchestrator: per mutating tier, run optional pre-op seed hook (ops.py pre_<op>) → perform the op
  ONCE (harness-owned) → run generic assertion (unless opted out) AND overlay assertion, both against
  the shared post-op deployment. Op results passed op→assertion via run-scoped CCCI_OP_STATE_FILE.
- opt-out: CCCI_SKIP_GENERIC / CCCI_SKIP_GENERIC_<OP> / recipe_meta.SKIP_GENERIC (declarative).
- generic.py: split do_* into op primitives (perform_upgrade/backup/restore) + assertions
  (assert_upgraded/backup_artifact/restore_healthy) reading op_state(); deployed_identity now returns
  {version,image,chaos} (chaos label ready for HC1).
- generic test_<op>.py + all 6 recipe overlays migrated to assertion-only; pre-op seeding moved to
  per-recipe ops.py (pre_upgrade/pre_backup/pre_restore). install overlays unchanged (no op).
- deploy-count stays 1 (op primitives never call deploy_app). lint PASS; 8 unit tests PASS on cc-ci.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/_generic/test_backup.py

@@ -1,9 +1,10 @@
-"""Generic BACKUP tier (Phase 1d DG3) — recipe-agnostic, backup-capable recipes only.
+"""Generic BACKUP tier (Phase 1d DG3 + Phase 1e HC3) — recipe-agnostic, assertion-only.
 
-Runs `abra app backup create` against the shared live deployment and asserts a snapshot artifact is
-produced (abra app backup snapshots is non-empty). Honest limit: the generic verifies the backup
-MECHANISM, not app-specific data integrity — that's a recipe overlay (test_backup.py seeds a marker).
-For recipes that declare no backup config the orchestrator skips this tier as N/A (not a failure)."""
+The orchestrator ran `abra app backup create` ONCE against the shared live deployment and recorded
+the produced snapshot id in the run-scoped op state. This tier ASSERTS a snapshot artifact was
+produced — it does NOT perform the op. Honest limit: the generic verifies the backup MECHANISM, not
+app-specific data integrity — that's a recipe overlay (test_backup.py). Runs by default ALONGSIDE any
+overlay (additive). For recipes that declare no backup config the orchestrator skips this tier (N/A)."""
 
 import os
 import sys
@@ -13,5 +14,4 @@ from harness import generic  # noqa: E402
 
 
 def test_backup_artifact(live_app, meta):
-    snaps = generic.do_backup(live_app)
-    assert snaps, "backup produced no snapshot artifact"
+    assert generic.assert_backup_artifact(live_app), "backup produced no snapshot artifact"