SAFETY-79: CI fixes - MUTATION.md pointer, no key-taking helper, fixture sized on the aim

test_peakguard's over-limit fixture now sizes its load against
cap - margin, so the floor it asks for is exact wherever in the quarter
the suite runs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UBtqPrG1mDLXzTEBnhEkkV

goodwe_controller/test_peak_margin.py

@@ -11,6 +11,8 @@ has the record. Drives the REAL Controller through tools/safety79_identity.py.
 3. The bill and the reports still use the real cap.
 4. Each call site in main.py passes the value its side needs.
 5. The setting: default, range, refusals in plain words.
+
+Mutations (MUTATION.md, purged copies) are listed in the pull request.
 """
 
 import ast
@@ -219,14 +221,8 @@ check("test_aim_w: `peak_aim_w()` is cap - margin, and the forecast sizing "
 print("\n5. the setting")
 
 
-def _cfg_pair(key):
-    """(default, schema) lines for `key` at two spaces in config.yaml."""
-    with open(os.path.join(HERE, "config.yaml"), encoding="utf-8") as f:
-        hits = re.findall(rf"^  {key}:\s*(\S+)", f.read(), re.M)
-    return hits
-
-
-_hits = _cfg_pair("peak_margin_w")
+with open(os.path.join(HERE, "config.yaml"), encoding="utf-8") as f:
+    _hits = re.findall(r"^  peak_margin_w:\s*(\S+)", f.read(), re.M)
 print(f"    config.yaml: {_hits}")
 check("config.yaml ships 50, int(0,500), and the in-code mirror matches",
       _hits == ["50", "int(0,500)"]