feat(tariff): whole-window package pricing mode (packageMinor)

A windowed card can now charge ONE total for any presence in its window —
the real night rate ("20:00–07:00 = 400, leave earlier and it's still
400"), which the per-increment flatMinor could not express (park-buzi's
"night 400" card billed 400/HOUR). Engine charges once per contiguous run
of increments the card wins, tracked across rolling-day segments so a
night crossing the 24h boundary charges once; out-of-window increments
price by the base card as usual.

Operator decisions (2026-07-05): per-occurrence repeat (two nights = two
charges), any-touch-pays-full, windowed cards only (a base "price per
day" is a 1-row up-to table). Validator: mutually exclusive with
flat/blocks/steps, no per-card cap, forbidden on the defaultCard.
flatMinor docs clarified as PER INCREMENT. 6 new engine tests.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

wiki/concepts/tariff-time-tiers.md

@@ -2,7 +2,7 @@
 type: concept
 tags: [parking, domain, business, pricing, design]
 sources: [parksql2017-legacy-schema]
-updated: 2026-06-18
+updated: 2026-07-05
 status: settled
 ---
 
@@ -140,7 +140,22 @@ case stays one rate card; tiers are opt-in.
   `DEFAULT_VEHICLE_CATEGORY` in `@parking/shared`). Per-relay capture (a "bus lane") is the future
   seam, mirroring per-relay direction.
 - **Flat rate** is a first-class card body (`flatMinor`, mutually exclusive with `blocks`). A flat V1
-  is published as a single open-ended block (V1 has no flat field).
+  is published as a single open-ended block (V1 has no flat field). ⚠ `flatMinor` is **per billing
+  increment** (an hourly flat rate at increment 60) — NOT a whole-stay/whole-window price. This was
+  misread in the field (park-buzi published a "night 400" believing it covered the night; it billed
+  400/h, 2026-07-05) — the UI now labels it "Flat price / hour" and the whole-window need got its own
+  mode:
+- **WINDOW PACKAGE (`packageMinor`, 2026-07-05 — windowed cards only).** "Any presence in this
+  window = ONE total" (the real night rate: 20:00–07:00 = 400, leave earlier and it's still 400).
+  Decisions (operator, 2026-07-05): charged **once per occurrence** (a stay touching two nights pays
+  twice); **any touch pays full** (an 06:30 arrival before the 07:00 close pays the whole package —
+  package pricing's accepted sharp edge); **not offered on the base card** (a base "one price per
+  day" is a 1-row up-to table — no duplicate concept). Engine: one charge per **contiguous run of
+  increments the card wins**, tracked across rolling-day segments so a night crossing the 24h
+  boundary charges once; out-of-window increments price by the base rate as usual; the charge lands
+  in the day segment where the occurrence starts (that day's default-card cap applies). Mutually
+  exclusive with flat/blocks/steps + no per-card cap (the package IS the window's total); validator
+  enforces both and the composer offers the mode only on tier cards.
 - **UI** (`TariffComposer.tsx`): default card **front-and-centre** (flat/ladder toggle + cap); tiers
   under a collapsed **"Advanced: time & seasonal tiers"** disclosure (window builder — dow checkboxes,
   optional date range, optional hour range with an overnight hint; category; priority; flat/ladder