MAINT-21: tests read and patch the Controller through tools/main_files.py

Prepares the split of app/main.py's Controller into files by job, with no app
change. tools/main_files.py gives a test the text and the AST of main.py plus
the files split from it, and `live`, which sets a global in every file whose
functions read it (and raises when none does). Tests that read main.py's
source, and tests and replay tools that patch a main global (datetime,
compute, resolve, _mono, WRITE_BUDGET_S, ...), go through it, so they pass on
this layout and on the split one. test_split_patches.py fails when a test or
tool patches an app.main attribute that main.py no longer reads, or that
another file also reads. tools/maint21_same_ast.py proves every function,
method and module-level assignment of main.py at the base is found unchanged
in its new file.

Co-Authored-By: Claude <noreply@anthropic.com>

goodwe_controller/test_refusal_units.py

@@ -50,6 +50,9 @@ from app import control
 from app.control import PROBE_EVERY_S, PROBE_S, PROBE_W
 from app.main import Controller
 from app.arbiter import P_LOOP, P_PEAK, P_SAFETY, Claim, resolve
+import os  # noqa: E402
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "tools"))  # noqa: E402
+import main_files  # noqa: E402
 import app.main as m
 
 fails = []
@@ -177,7 +180,7 @@ def run(load, cut, dur, *, soc=None, jitter=False, old=False, events=None,
         c.auto = True
         if old:
             _off(c)
-        real_dt = m.datetime
+        real_dt = main_files.live.datetime
         clock = [0.0]
 
         class _DT(real_dt):
@@ -185,7 +188,7 @@ def run(load, cut, dur, *, soc=None, jitter=False, old=False, events=None,
             def now(cls, tz=None):
                 return BASE + timedelta(seconds=clock[0])
 
-        m.datetime = _DT
+        main_files.live.datetime = _DT
         rows = []
         trips = {u: 0 for u in UNITS}
         was = {u: False for u in UNITS}
@@ -211,7 +214,7 @@ def run(load, cut, dur, *, soc=None, jitter=False, old=False, events=None,
                     db=c.inverters[1].delivery_wd.tripped))
                 t += dt
         finally:
-            m.datetime = real_dt
+            main_files.live.datetime = real_dt
         return rows, trips, c
     return asyncio.run(go())