feat: reconcile Alpaca against the memory bank at startup

[mohammadp1001]

Why

While clearing the stranded SPY position from the 2026-08-10 run, Alpaca turned out to
be holding 113 shares of QQQ ($81,553) that the memory bank had no record of at all.

Nothing noticed, and nothing could:

• the monitor only ever iterates rows in the bank, so a position the bank has forgotten
  has no stop-loss, no exit window and no owner
• FR-019 gates a ticker on its open rows, so it cannot block a ticker it has no row for.
  The next run would have opened a second QQQ position on top of the untracked 113
  shares

The two sides drift for ordinary reasons. Recreating the bank is the only way to apply a
schema change (there is no migration tooling), and it wipes local rows while the broker
keeps holding the shares. A crash between placing an order and writing the row leaves the
mirror image.

What this adds

alphoryn run gains a startup reconciliation, step 5, right after the memory bank loads.
It classifies three disagreements:

Kind	Meaning
ORPHAN	Broker holds it, bank has no open row. Unmonitored exposure.
PHANTOM	Bank has an open row, broker holds nothing. The monitor can never close it.
QUANTITY_DRIFT	Both hold it, in different sizes.

It warns and continues; it does not block. A check that could itself stop trading
would be a worse problem than the drift it catches, so a broker that cannot be reached is
reported and the run proceeds.

--reconcile flattens the disagreement first. That is the only destructive path, and it
is never a side effect of a plain run.

Design notes

CLOSED_RECONCILED sits outside both the feedback-blocking and feedback-due status
sets. The ticker is freed, and the feedback agent never sees the position. Its outcome
was never observed, so there is no honest thesis judgment to make.

exit_price is left NULL, not given a value. 0.0 would report a total loss and the
entry price would report a flat trade. Both are inventions; NULL says the one true thing,
which is that nobody knows. This needed a new MemoryBank.mark_position_reconciled
rather than reusing update_position_close, which requires a price.

The bank is written only after the broker confirms its close, so a failed close cannot
manufacture the very drift this exists to catch.

Verified against the live account

Read-only run of the new check against real Alpaca and the real memory bank:

discrepancies: 1

  [ORPHAN] QQQ: Alpaca holds 113, the memory bank has no open position.
           It is unmonitored - no stop-loss, no exit window.

It reports the real orphan and stays silent about SPY, which both sides agree on (1 share
each). Nothing was modified.

Tests

688 passed, 100% coverage, ruff check alphoryn/ tests/ clean. Verified under CI's
credential-less environment (GOOGLE_APPLICATION_CREDENTIALS=/nonexistent/adc.json), not
just locally.

Three test modules that drive alphoryn run gained an autouse fixture stubbing the new
check, for the same reason the telemetry preflight needed one in #174: it builds a real
TradingClient, so leaving it live makes the suite pass or fail on whether the machine
happens to have credentials.

Note on a choice you may want to revisit

Warn-and-continue was chosen deliberately over blocking (exit 5). The tradeoff: an
operator who ignores the warning still runs with unmonitored exposure, and can still stack
a new position on top of an orphan. Blocking would prevent that outright, at the cost of
being unable to trade until the drift is cleared. The --reconcile flag exists so the fix
is one flag away either way.