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_modes_p4.py

@@ -37,6 +37,7 @@ sys.path.insert(0, os.path.join(HERE, "tools"))
 logging.disable(logging.WARNING)
 
 from named_absence import nth, present                         # noqa: E402
+import main_files                                              # noqa: E402
 import opt11p3_replay as rp                                    # noqa: E402
 from app import arbitrage, dayplan, homeview, modetrade, packmode  # noqa
 from app import priceruns, solarfc, validate                    # noqa: E402
@@ -777,7 +778,7 @@ check("battery modes off: the forecast sensor is never read", READS[0] == 0)
 print("7. the Batteries screen and the Simple view")
 rows, st_, c = run_day(SF_LS, fc=1.0, soc0={"a": 60.0, "b": 30.0},
                        hours=0.6)
-rp.m.datetime = datetime
+main_files.live.datetime = datetime
 sb = homeview.solar_block(c, c.solar_fc.at)
 check("the forecast line names the forecast, what is counted and when",
       sb["line"].startswith("Solar still to come today:")
@@ -812,14 +813,14 @@ check("a lost forecast says so: no forecast, Leftover solar solar only",
 c._charge_latch = latch
 # the latch ends at its end time; this replay ran in September, so ask at a
 # moment inside it
-_real_dt = rp.m.datetime
-rp.m.datetime = type("_DT", (datetime,), {"now": classmethod(
+_real_dt = main_files.live.datetime
+main_files.live.datetime = type("_DT", (datetime,), {"now": classmethod(
     lambda cls, tz=None: latch[0] - timedelta(hours=1))})
 check("OPT-34: with a charge under way (B charged in this run), the level "
       "stays: plan_targets() gives it (the line: test_opt34.py)",
       latch is not None and c.plan_targets() is not None
       and B in c.plan_targets() and c.plan_targets()[B] == c._plan_targets[B])
-rp.m.datetime = _real_dt
+main_files.live.datetime = _real_dt
 check("the Why line wins over 'saves its power' only while holding",
       homeview.battery_why(modes_on=True, mode="leftover_solar", off=False,
                            reading=True, phase="idle", shadow=False,