MAINT-21: comments only - trim restated notes, add DECISIONS pointers

No code change: tools/maint21_same_ast.py and tools/maint20_same_code.py HEAD~
both print OK, and the -OO code objects are the same.

- Trims 56 comment and docstring lines (2088 -> 2032) in app/main.py and the
  new files that only restated their MAIN-orchestration.md bullet, each cut to
  its first sentence and a pointer. What the cut comments said and the bullet
  did not is now in the bullet: why a SAFETY-02 latch is restored, why the
  SAFETY-30 site check is not armed at one inverter, the SAFETY-18 re-derive,
  the MAINT-05 one-config rule, the OPT-09 sizing rules, the "no plan" row,
  the 5 400 s age bound, and the guard being the only latch repair.
- Adds the missing DECISIONS pointers on the SMA-10, SAFETY-137 and SMA-2
  comments (FALLBACK_BUDGET_S, write_setpoint, _await_inflight,
  _release_last, the retry wait, the failed-release branch, release_zero_sent,
  the in-flight write, the stop_event hand-back, the SMA-2 read and driver).
- DECISIONS/SAFETY-32: the stale `main.py:932-936` now names
  Controller.pack_floor_soc.
- main.py's docstring and import block say where the Controller's parts are.

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

goodwe_controller/app/rows.py

@@ -40,11 +40,8 @@ def why_key(winner: str, claims) -> str:
 def tariff_plan_row(plan, tick_words: str, *, age_s, horizon_h: float,
                     provider: bool, max_age_s: float) -> str:
     """The *Tariff* status row: the 30 s tick's sentence AND the provider plan
-    (TARIFF-11): two sources, two clocks, and the row says so. The plan is
-    stamped with its own age from `tariff_at` (not moved on a kept plan,
-    TARIFF-12), up to TARIFF_MAX_AGE_S (5400 s); `age_s` is the caller's
-    measurement. "No plan" is said aloud on a site that configured a provider.
-    DECISIONS/MAIN-orchestration.md."""
+    (TARIFF-11), each with its own clock. "No plan" is said aloud on a site
+    that configured a provider. DECISIONS/MAIN-orchestration.md."""
     # UX-08: plain words, every figure kept. The tick's sentence is "now"; the
     # plan carries its own age.
     if plan is None:
@@ -58,12 +55,9 @@ def tariff_plan_row(plan, tick_words: str, *, age_s, horizon_h: float,
 
 def arbitrage_row(*, on: bool, decision, decided_at, cycle_at, now,
                   why: str) -> str:
-    """The *Arbitrage* status row: three states (TARIFF-11): off (not armed),
-    armed with no decision this cycle (`why` is the loop's reason), or a
-    decision with its age.
-    `on` is read from the options, never inferred from `decision is None`:
-    `cycle()` returns at the input hold before `self.arb = None`, so the old
-    row named an option that was ON. The age is always printed, even 0.
+    """The *Arbitrage* status row: off, armed with no decision this cycle
+    (`why` is the loop's reason), or a decision with its age (TARIFF-11).
+    `on` is read from the options, never inferred from `decision is None`.
     DECISIONS/MAIN-orchestration.md."""
     # UX-08: plain words; the setting is named by its label.
     if not on: