fix(payments): soft-warn payout mismatch + surface manual payouts to schools (#499)

[guillermoscript]

Description

Part of the payout money-accuracy work (epic #493, phase 2). Two independent gaps closed:

1. No overpayment guardrail. markPayoutPaid only validated amount > 0 — a typo (extra zero, wrong decimal) recorded silently with no confirmation beyond the dialog's pre-filled suggested amount.
2. No manual-payout visibility for schools. The tenant-facing payout page (/dashboard/admin/payouts) already existed and is already RLS-scoped to the tenant's own rows, but its query and copy assumed Stripe Connect only — manually-recorded payouts (PayPal/Binance/Lemon Squeezy settlement) showed up with no note and copy that didn't fit them.

Changes made

• app/actions/platform/payouts.ts — markPayoutPaid now recomputes the tenant's current netOwed server-side (reusing the existing getPayoutsOwed(), never trusting a client-supplied value) and returns { status: 'warning', netOwed } instead of inserting when the entered amount is more than 10% off. A confirmMismatch flag lets the caller push through after the user confirms. No hard block — this is a soft warning, matching the issue's ask.
• components/platform/mark-payout-paid-dialog.tsx — on a warning response, the dialog stays open and shows an inline banner ("Amount differs from suggested payout — suggested $X, entered $Y") with the submit button relabeled "Confirm anyway"; editing the amount or note clears the pending warning so a corrected value gets re-checked.
• app/[locale]/dashboard/admin/payouts/page.tsx — the query now selects note and payout_method; a new "Method" column shows Manual vs. Stripe Connect with the note as a secondary line. Copy in messages/en.json / es.json no longer implies Stripe-only.

Type of change

• Bug fix (overpayment guardrail)
• Enhancement (tenant payout visibility)

Closes #499

Testing

• npm run typecheck — passes
• npm run lint — no new errors introduced (pre-existing baseline unrelated to these files unaffected; confirmed no errors under the three changed files)
• npm run test:unit -- payouts-owed — 18/18 passing (pure balance-computation logic untouched by this change)
• Manually verified end-to-end in the local app (see GIF + screenshots in the comment below): seeded a $250 platform-settled transaction for Default School (netOwed $200 at 80% split), entered $20 in "Mark as Paid" → inline mismatch warning appeared → "Confirm anyway" recorded it → tenant's /dashboard/admin/payouts immediately showed the payout with Method = Manual and the note.

QA verification steps

1. As a super admin, open the payouts dashboard for a tenant with netOwed > 0. Enter an amount within ~10% of the suggested value and submit — it should record in one step, no warning.
2. Repeat with an amount far from the suggested value (e.g. 10x smaller) — a warning banner should appear instead of submitting; the button should read "Confirm anyway". Clicking it should complete the payout.
3. Edit the amount after a warning appears — the warning should clear, requiring a fresh check on next submit.
4. As that tenant's school admin, open /dashboard/admin/payouts — the newly recorded manual payout should show a "Manual" method and its note, and the page description should no longer say "Stripe Connect" exclusively.

Screenshots

Before/after screenshots and a verification GIF are posted as a comment on this PR.

[guillermoscript]

Visual verification for #499 — before/after screenshots and a recorded GIF of the flow.

Super admin — Mark as Paid mismatch warning (Before → After)

Before: single-step submit, no check against the suggested amount.

After: entering an amount far from the suggested netOwed now shows the mismatch banner and requires "Confirm anyway" before it records.

Tenant admin — payout history visibility (Before → After)

Before: page copy and columns assumed Stripe Connect only; no way to see a manually-recorded payout's method or note.

After: a Method column (Manual vs. Stripe Connect) with the note shown, and the copy no longer implies Stripe-only.

Flow recording

End-to-end: super admin enters an amount far below the suggested payout, sees the warning, confirms anyway, then the tenant admin immediately sees the recorded manual payout with its note.

Please give this a visual once-over before merging.

[guillermoscript]

Merged as 3a367631. Final scope shipped as planned, no changes during review:

• markPayoutPaid recomputes netOwed server-side and soft-warns (doesn't block) when the entered amount is more than 10% off the suggested payout, requiring a "Confirm anyway" click to push a mismatched amount through.
• The tenant-facing /dashboard/admin/payouts page now surfaces payout_method/note, with a Method column distinguishing manual payouts from Stripe Connect disbursements, and copy that no longer implies Stripe-only.
• Verified end-to-end locally (screenshots + GIF above): a mismatched amount triggers the warning banner, "Confirm anyway" completes it, and the tenant admin immediately sees the recorded manual payout with its note.
• Checks: typecheck/lint clean (no new errors), payouts-owed unit suite 18/18, CI verify green.

No follow-ups spun off from this one — closes out #499.