fix: emit export pickup times as clock readings without an offset

docs/api-consumer-guide.md

@@ -190,7 +190,7 @@ an error: it returns `200` with an empty `data` array and the usual `meta`.
           "city": "Essen",
           "street": "Am Hauptbahnhof (Südausgang Fernbushaltestelle)",
           "time": "20:15",
-          "datetime": "2026-12-25T20:15:00+01:00"
+          "datetime": "2026-12-25T20:15:00"
         }
       ]
     }
@@ -225,12 +225,17 @@ rest. `total` is the row count **after** skips, and `totalPages` is `ceil(total
 
 **Pickup times.** `pickups` is in **source order** — the order the boarding list is driven in — not sorted by time.
 
-- `time` is `"HH:MM"` for display; `datetime` is the same moment as a full ISO-8601 string with a
-  `Europe/Berlin` offset (`+01:00` / `+02:00` depending on DST). **Prefer `datetime`.**
-- Upstream states a boarding time either as a full date and time or as a bare time. A bare time is resolved
-  against the departure date and, where the sequence demands it, rolled onto the following calendar day — so an
-  `02:15` listed after a `23:59` comes back on the next date, not the same one. `datetime` is emitted for
-  bare-time sources too, and carries that resolution.
+- `time` is `"HH:MM"` for display; `datetime` is the same reading with its date resolved, as
+  `YYYY-MM-DDTHH:MM:SS` **without an offset**. **Prefer `datetime`.**
+- Both are upstream's local clock readings, not instants: coaches are timetabled in plain clock times. A stop at
+  `02:45` on the night the clocks go forward comes back as `…T02:45:00`, although that hour does not exist in
+  `Europe/Berlin`, and a stop in the hour repeated when the clocks go back passes through unchanged. Do not attach
+  an offset to compare or sort them; they already sort correctly as strings.
+- Upstream states a boarding time either as a full date and time, taken verbatim, or as a bare time. A bare time
+  takes the departure date (`dateFrom`), and moves to the following day if it would otherwise fall before the
+  latest full date and time **anywhere** in the same boarding list, whatever its position. So on a departure
+  dated 26.12. whose list also dates a stop `26.12. 23:59`, a bare `02:15` comes back as `…12-27T02:15:00`.
+  `datetime` carries that resolution for bare-time sources too.
 - A boarding point with no time upstream comes back with **both** `time` and `datetime` null. They are always
   null together.
 - Caveat: where upstream states full datetimes for a whole boarding list, those dates are taken verbatim. Some
@@ -313,7 +318,7 @@ returns it in one page.
           "city": "Frankfurt",
           "street": "Flughafen (P36 zwischen Terminal 1 und 2)",
           "price": 5.9,
-          "datetime": "2026-12-03T23:30:00+01:00"
+          "datetime": "2026-12-03T23:30:00"
         }
       ],
       "guide": null
@@ -380,10 +385,11 @@ such as for arriving by car.
 | 89 | Leistungen Events |
 | 90 | Leistungen Transport |
 
-**Pickups.** Outbound boarding points only, in source order. `datetime` follows the same resolution rules as in
-`GET /api/exports/travels`, including rolling a bare time past midnight onto the next day. There is no separate
-`time` field; format `datetime` for display. `price` is the outbound boarding surcharge exactly as upstream states
-it: `null` where upstream states none. It is not levelled against the return leg. An id absent from
+**Pickups.** Outbound boarding points only, in source order. `datetime` is resolved and formatted exactly as in
+`GET /api/exports/travels` — a clock reading without an offset, `null` where upstream states no time — including
+rolling a bare time past midnight onto the next day. There is no separate `time` field; format `datetime` for
+display. `price` is the outbound boarding surcharge exactly as upstream states it: `null` where upstream states
+none. It is not levelled against the return leg. An id absent from
 `GET /api/pickups` is emitted with `code`, `city` and `street` null and counted in `pickupsWithoutMasterData`. An id
 of `0` is emitted as-is but not counted.