review(samever): Adversary orientation — samever phase started; awaiting M1 claim

machine-docs/REVIEW-samever.md

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+# REVIEW — phase `samever` (Adversary writes here)
+
+**Phase:** samever — step back to older base when canonical == head version (no same-version upgrade)
+**SSOT:** `/srv/cc-ci/cc-ci-plan/plan-phase-samever-older-base-fallback.md`
+**Adversary loop started:** 2026-06-17T04:09Z
+**Adversary clone:** /srv/cc-ci/cc-ci-adv
+
+---
+
+## Gate verdicts
+
+(none yet — waiting for Builder M1 claim)
+
+---
+
+## Orientation @2026-06-17T04:09Z
+
+Phase `samever` plan created 2026-06-17T03:56Z. Builder has not yet started (no STATUS-samever.md).
+
+**Root cause confirmed (cold-read of resolver, lines 133–148 of run_recipe_ci.py):**
+```python
+rec = canonical.read_registry(recipe)
+if rec and rec.get("version"):
+    return BasePlan(
+        "version",
+        rec["version"],
+        None,
+        f"last-green (warm canonical, status={rec.get('status')})",
+    )
+```
+The warm-canonical path returns `canonical["version"]` WITHOUT checking if it equals the head version.
+The resolver is not passed the head's semantic version (only `head_ref`, a commit sha), so it cannot compare.
+
+**Current unit tests (8 tests in tests/unit/test_upgrade_base.py) — none cover canonical==head:**
+- test_upgrade_not_in_stages_skip
+- test_expected_na_upgrade_skip_even_with_canonical_and_override
+- test_explicit_override_wins_over_canonical
+- test_last_green_warm_canonical_is_primary  ← uses canonical["version"]="0.6.0+3.1.1", HEAD="aaaa1111head" (different version — correct but doesn't test the same-version edge)
+- test_main_tip_fallback_when_no_last_green
+- test_head_equals_main_tip_skip
+- test_no_canonical_no_main_skip
+- test_expected_na_other_rung_does_not_suppress_upgrade
+
+**Key utilities available for the fix:**
+- `warm_reconcile.recipe_tags(recipe)` — returns all git tags from recipe clone
+- `warm_reconcile.sort_versions(tags)` — ascending sort of version tags (coop-cloud semver)
+- `warm_reconcile.latest_version(tags)` — the newest tag
+- Head version read from compose.yml: `coop-cloud.${STACK_NAME}.version` label at `abra.recipe_dir(recipe)/compose.yml` (head checkout already at that path when resolver runs)
+
+**M1 verification plan (what I'll cold-verify when claimed):**
+1. Resolver reads head version from compose.yml (inspect the parsing — look for compose YAML read + `coop-cloud.*version` label extraction)
+2. New chain: override → (canonical if canonical≠head_version) → (newest older published if canonical==head_version) → main-tip → skip
+3. Unit tests added: at minimum canonical==head→step_back, canonical≠head→unchanged, no_older_published→skip, version ordering correct
+4. Run `python -m pytest tests/unit/test_upgrade_base.py -v` cold from own clone
+5. Confirm OVERRIDE, EXPECTED_NA, main-tip, skip paths are untouched (regression: existing 8 tests still pass)
+6. Teeth check: a "broken base" scenario should still fail (unit test or from plan F1d-2 evidence)
+
+**M2 verification plan:**
+1. Cold-on-latest run on an enrolled recipe whose canonical == latest (seed the canonical to latest, then trigger cold run)
+2. Evidence in logs: `base_version < head_version` (not a no-op, not a skip)
+3. Re-run discourse #4 or equivalent version-bump PR → UNAFFECTED (canonical→head path still uses canonical)
+4. Spot-check ≥1 other recipe
+
+---
+
+## Adversary findings
+
+(empty — phase not yet started)
+
+---
+
+## Break-it probes log
+
+(none yet)