Merge phase 26 school seed.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/protocol.md

@@ -32,6 +32,8 @@ the wire format is unambiguous, and the client formats it back in UTC.
 
 Everything the main menu needs in one request. `schoolWeekDays` is 5–7 working days counted
 from Monday (five is Mon–Fri; six adds Saturday). It is a school rule, not a catalog def.
+`seed` is the roster generator seed: it is not the school id. Share it to recreate the same
+people; it does not change on a living school.
 
 ```json
 {
@@ -40,7 +42,7 @@ from Monday (five is Mon–Fri; six adds Saturday). It is a school rule, not a c
   "gameMinutesPerRealSecond": 5,
   "schoolWeekDays": 5,
   "schools": [
-    { "id": 1, "name": "Гимназия №14", "gameTime": "2012-03-31T07:35:00Z", "running": false, "speedIndex": 1, "modIds": ["core"] }
+    { "id": 1, "name": "Гимназия №14", "gameTime": "2012-03-31T07:35:00Z", "running": false, "speedIndex": 1, "modIds": ["core"], "seed": 1847291 }
   ]
 }
 ```
@@ -117,7 +119,8 @@ Body:
   "modIds": [],
   "map": null,
   "nameSetId": "Slavic",
-  "nativeLanguage": null
+  "nativeLanguage": null,
+  "seed": null
 }
 ```
 
@@ -129,6 +132,8 @@ the same catalog. Omit `map` (or send `null`) to use that pack set's default lay
 `Slavic`). Unknown ids return `400` `unknown-name-set`.
 `nativeLanguage` is a skill from that set's `nativeLanguages`. Omit it (or send `null`) to pick
 one from the school seed. An id that is not in the set returns `400` `unknown-native-language`.
+`seed` is an optional integer. Send it to reproduce a known school; omit it (or send `null`) and
+the server rolls one. Existing saves keep the seed already stored in the people file.
 
 | Status | Meaning |
 | --- | --- |