Add timetable planning and related tests to school simulation

- Introduced a new project for timetable planning, dependent on HSchool.Content.
- Updated documentation to reflect the addition of timetable planning and its dependencies.
- Added tests for timetable planning to ensure deterministic behavior with the same staff and map.
- Revised architecture documentation to include the new HSchool.Schedule component and its interactions.

docs/architecture.md

@@ -34,14 +34,17 @@ there is no UI on the server.
 | --- | --- |
 | `src/HSchool.Protocol` | Binary wire format. No dependencies, referenced by everything that talks to the socket. |
 | `src/HSchool.Content` | JSONC defs, inheritance, patches, locales, map instance and connectivity. No Arch, no ASP.NET. |
+| `src/HSchool.People` | Roster generation from catalog, map and seed. No Arch, no ASP.NET. |
+| `src/HSchool.Schedule` | Timetable from curriculum, assignments and map. No Arch, no ASP.NET. |
 | `src/HSchool.Simulation` | Schools, the game clock, the Arch ECS world. Holds a frozen catalog and map; no HTTP. |
 | `src/HSchool.Server` | ASP.NET Core host: the menu API, the WebSocket endpoint, per-school workers, `mods/` and `saves/`. |
 | `src/HSchool.ServiceDefaults` | Shared Aspire wiring: OpenTelemetry, health checks, service discovery, resilience. |
 | `src/HSchool.AppHost` | Aspire orchestration: which resources run and how they find each other. |
 | `src/HSchool.Client` | Vite + TypeScript UI: main menu, creation form, the school screen. |
 
-Dependency direction is one-way: `Protocol ← Server → Simulation → Content`. Nothing in
-`Simulation` or `Content` knows about HTTP, and nothing in `Protocol` knows about schools.
+Dependency direction is one-way: `Protocol ← Server → Simulation → People → Content`, and
+`Schedule → Content`. Nothing in `Simulation` or `Content` knows about HTTP, and nothing in
+`Protocol` knows about schools.
 
 ## Two channels, on purpose