Retire in-code comments that outlived what they described (B-69)

- app/tx/reconcile.py called the payout retry "a future payout-retry
  routine — still an open gap". It shipped as B-26: clearing payout_txid
  leaves the round in exactly the state _retry_payout_if_due picks up, so
  an abandoned payout rebuilds itself and the log line next to it is an
  alert, not the recovery path. Reading it the old way, an operator would
  go hand-fix a round the scheduler was already retrying.
- app/db/base.py sized the SQLite busy timeout against "five concurrent
  background tasks" and then listed only the non-listener ones; the
  lifespan starts six.
- The third item (app/auth/routes.py citing B-31 where it meant B-33) was
  already correct in the tree; the test pins it so it stays that way.

tests/unit/test_code_comments.py derives the task count from the lifespan's
own create_task calls rather than restating it, so the comment fails the
next time a task is added or removed instead of quietly going stale again.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -8,7 +8,7 @@ The user communicates in Italian in chat — reply to them in Italian. Everythin
 
 ## Project status
 
-All 10 stages of the original build order are code-complete and unit-tested — 345 tests, all under `tests/unit/` (`tests/integration/` is an empty package). Beyond them: Docker + Caddy deployment, admin dashboard (`/admin`), static test UI (`/`), pending-inclusive balance display, an SSE push channel layered over the original polling, self-service password change + admin password reset, and the reconciliation/corroboration machinery below.
+All 10 stages of the original build order are code-complete and unit-tested — 349 tests, all under `tests/unit/` (`tests/integration/` is an empty package). Beyond them: Docker + Caddy deployment, admin dashboard (`/admin`), static test UI (`/`), pending-inclusive balance display, an SSE push channel layered over the original polling, self-service password change + admin password reset, and the reconciliation/corroboration machinery below.
 
 Verified on mainnet with real money: registration + address derivation, deposit crediting (1-conf), a real 10 PLM bet (broadcast → confirmed → change credited back), and one full round cycle (close → draw on a real block hash → 70/30 payout with sat math checked against the broadcast tx → confirmation → close → next round auto-opened). **Withdrawal and the RBF bump path have never been exercised against a live broadcast** — unit-tested only.
 
@@ -33,7 +33,7 @@ PYTHONPATH=. python scripts/decrypt_master_key.py     # ops recovery: decrypt+pr
 PYTHONPATH=. python scripts/encrypt_master_key.py     # ops bootstrap: import an externally-generated xprv (--overwrite to replace)
 PYTHONPATH=. python scripts/electrum_smoke_test.py    # manual check: connect, handshake, subscribe to headers, print the tip
 
-python -m pytest                                      # all 345 tests
+python -m pytest                                      # all 349 tests
 python -m pytest tests/unit/test_hd.py                # one file
 python -m pytest tests/unit/test_hd.py::test_derivation_is_deterministic   # one test
 ```