Add one shared builder for signed paid booking rows

[stefan-burke]

This pull request is the next staged-checkout foundation step. It creates one pure, canonical representation of the signed paid booking rows that both ordinary payment completion and the later staged runtime can use, and lifts the shared booking date/duration rules into their own helper alongside it — the row builder depends directly on those rules, so splitting them would only add ordering without isolating meaningful risk.

What changes

• src/shared/booking-date-fields.ts (new): the single definition of how a booking row's date and durationDays are derived from a listing's type and the buyer's chosen span. A customisable_days listing uses the chosen dayCount; a non-customisable daily listing uses its fixed duration_days; a standard listing spans one dateless day. A missing dayCount (a legacy signed session without day_count) still means one day.
• src/shared/booking-lines.ts (new): orderBookings — an explicitly typed builder for the signed paid listing_attendees rows. It builds one row per signed line carrying its listing, quantity, date, duration, package path, and paid price; expands child lines into one row per (child, parent) when allocations are present; and stamps a folded child with its parent's package only when that parent books through exactly one path.
• src/features/api/payment-processing/create.ts: the paid webhook's row construction/allocation/package-stamping block is replaced by one orderBookings call. Payment finalization and error behaviour are unchanged. The DB layer still coerces an undefined pricePaid to 0, so removing the old ?? 0 makes no observable difference; it just lets a genuine 0 (a free line that was still signed) stay distinct from an omitted price on the in-memory rows.
• src/features/api/payment-processing/store-refund.ts: only the bookingDateFields import moves to the shared helper.
• src/features/public/ticket-payment.ts: uses the shared bookingDateFields for its existing availability and free-booking callers. Current ResponseHandler and modular capacity behaviour are preserved.
• src/shared/db/attendees/order-parents.ts: expandChildAllocations and expandBooking are made generic over T extends ListingBooking so any required row fields a caller carries on each booking survive the expansion.

Behaviour contract

• Listing, quantity, date, duration, package path, allocation, input order, and paid price are all preserved.
• A pricePaid of 0 is kept distinct from an omitted price.
• Standard non-customisable rows are dateless with duration 1; daily/customisable combinations keep the current date/day rules; a missing legacy day_count means one day.
• Child allocations preserve total quantity and exact total paid price; the last split row absorbs the rounding residue; every expanded row shares one order token.
• A folded child is stamped with a parent package only when that parent has one unambiguous package path. Mixed and standalone parent paths do not falsely stamp children.
• The current main in-memory standalone package contract is kept, including packageGroupId 0 where existing writers expect it.

Tests

• test/shared/booking-lines.test.ts (new): focused pure tests for standalone and tagged package rows, pricePaid 0 versus omitted, empty and multiple allocations, parentless remainder, exact price conservation, shared order token, sole-parent stamping, and mixed-parent non-stamping.
• test/shared/booking-date-fields.test.ts (new): the standard/daily/customisable cases moved out of test/features/public/ticket-payment.test.ts, plus a missing-dayCount case and a non-finite-clamp case.

Scope excluded

No checkout_stages, migrations, activation, rollback fences, refund lifecycle, cleanup, expiry, backup split, admin locks, staged callbacks, webhook reconciliation, or wholesale copies of the old reference branch. Newer work on main from PRs #1821–#1826 and #1828 is preserved. Build on the current main commit 31417124; #1827 (Stripe webhook setup) was still open at push time, so no main re-merge was needed.

Verification

Biome (lint:ci) and CPD (src + test configs) both run clean. Full typecheck and the test suite are left to CI and the commit hook.

Summary by CodeRabbit

• New Features
  • Added shared helpers to consistently compute booking dates/durations and to generate signed paid booking rows, including parent/child allocation expansion and package stamping.
• Bug Fixes
  • Ensures booking date/duration behavior is identical across payment and refund flows.
  • Preserves explicitly provided pricePaid: 0 while omitting pricePaid when not present to allow correct downstream defaults.
• Tests
  • Added/updated test coverage for booking date/duration logic and signed paid booking row expansion (allocations, price conservation, and package assignment).

[coderabbitai]

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• test/shared/booking-lines.test.ts

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📝 Walkthrough

Walkthrough

Booking date derivation and allocation-aware booking construction are centralized in shared modules. Attendee creation uses the shared builder, while payment and refund flows import the shared date helper. Tests cover date rules, price omission, allocation expansion, price conservation, and package stamping.

Changes

Booking row centralization

Layer / File(s)	Summary
Centralize booking date derivation src/shared/booking-date-fields.ts, src/features/public/ticket-payment.ts, src/features/api/payment-processing/store-refund.ts, test/shared/booking-date-fields.test.ts, test/features/public/ticket-payment.test.ts	Booking date and duration logic moves to a shared helper, with callers and tests updated accordingly.
Build allocation-aware booking rows src/shared/booking-lines.ts, src/shared/db/attendees/order-parents.ts, test/shared/booking-lines.test.ts	orderBookings creates signed booking rows, preserves omitted versus zero prices, expands allocations, stamps package metadata, and retains extra row fields through generic expansion.
Use canonical rows in attendee creation src/features/api/payment-processing/create.ts	createAttendeeForSession delegates booking construction to orderBookings before atomic booking creation.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Sequence Diagram(s)

sequenceDiagram
  participant createAttendeeForSession
  participant orderBookings
  participant expandChildAllocations
  createAttendeeForSession->>orderBookings: signed lines, date, dayCount, allocations
  orderBookings->>expandChildAllocations: allocation-aware booking rows
  expandChildAllocations-->>orderBookings: expanded rows with quantities and prices
  orderBookings-->>createAttendeeForSession: ListingBooking rows

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🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: introducing a shared builder for signed paid booking rows.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

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• Create PR with unit tests
• Commit unit tests in branch split/booking-lines

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[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/features/api/payment-processing/create.ts`:
- Around line 264-274: Update the booking-line mapping inside orderBookings to
conditionally spread pricePaid only when
paidByIntentItem.get(pricingIntent.items[index]!) is defined, preserving 0 as a
valid value and omitting the property otherwise; keep the remaining fields
unchanged.

In `@test/shared/booking-lines.test.ts`:
- Around line 88-89: Replace the compound .every(...).toBe(true) assertions in
the booking-lines test with explicit per-row assertions for orderToken and
parentListingId, including the checks around the additional assertions at lines
108-113. Keep the result length and row-presence validation intact so dropped or
incorrect rows are detected with row-specific failure output.
- Around line 162-170: Remove the unnecessary nullish fallback from the
childPackageFor helper’s find result. Keep the non-null assertion on the
matching listing and return its numeric packageGroupId directly.

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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📥 Commits

Reviewing files that changed from the base of the PR and between 2c5eb0a and 4a41789.

📒 Files selected for processing (9)

• src/features/api/payment-processing/create.ts
• src/features/api/payment-processing/store-refund.ts
• src/features/public/ticket-payment.ts
• src/shared/booking-date-fields.ts
• src/shared/booking-lines.ts
• src/shared/db/attendees/order-parents.ts
• test/features/public/ticket-payment.test.ts
• test/shared/booking-date-fields.test.ts
• test/shared/booking-lines.test.ts

💤 Files with no reviewable changes (1)

• test/features/public/ticket-payment.test.ts

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test/shared/booking-lines.test.ts`:
- Around line 173-181: Update the childPackageFor helper to return number rather
than number | undefined, and assert the guaranteed packageGroupId invariant when
retrieving the listingId 20 result. Keep the existing orderBookings lookup and
return behavior unchanged.

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
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Configuration used: Organization UI

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Run ID: a26de6e7-6261-4421-8518-d147010e8c85

📥 Commits

Reviewing files that changed from the base of the PR and between 4a41789 and e24b94f.

📒 Files selected for processing (3)

• src/features/api/payment-processing/create.ts
• src/shared/booking-lines.ts
• test/shared/booking-lines.test.ts