Step 1: the Salty project, two modules, tests and the gym

Salty.uproject (UE 5.8) from the Third Person template with class redirects, the SaltyCore and Salty modules,
the three build targets, USaltyAssetManager calling InitGlobalData, Config/Tags with the 23 root namespaces,
Scripts/run-tests.sh, build.sh and Authoring/create_gym.py, L_Gym, Git LFS attributes and the placeholder test.
Template variants kept as reference (D-41). The four Fab packs stay out of the repository for now (~10 GB).
The editor serves the engine MCP plugin on 127.0.0.1:8000 through DefaultEditorPerProjectUserSettings.ini.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Docs/Spec/Architecture.md

@@ -246,3 +246,24 @@ Real ones, from the engine, that cost a day each if met in the wild rather than
 - **Dedicated server packages need the engine from source.** The launcher build compiles no server target. Play In
   Editor's "Run Dedicated Server" works on the launcher build and is the everyday test; the source build arrives when
   the first packaged server does.
+
+## What was built, and where it differs
+
+Step 1, 2026-09-16.
+
+- **Name and engine:** `Salty`, UE 5.8 launcher build (D-39, D-40). Modules `SaltyCore` and `Salty` as specified;
+  `SaltyServer.Target.cs` exists but the launcher build cannot compile it, so the dedicated server is proved through
+  Play In Editor (OD-04).
+- **The project started from the Third Person template, not empty.** Its plain character, game mode and controller
+  survive as `ATemplateCharacter`, `ATemplateGameMode`, `ATemplatePlayerController` (class redirects in
+  `DefaultEngine.ini`) and are the placeholder body until step 3 replaces them. The template's three variants stay as
+  reference only (D-41); they do not follow these conventions and nothing is built on them.
+- **`USaltyAssetManager` arrived in step 1**, earlier than the spec implies, because it is the one place
+  `UAbilitySystemGlobals::InitGlobalData` belongs and the cost was a file. No `PrimaryAssetTypesToScan` entries yet;
+  each definition class adds its own.
+- **Tags:** one `Config/Tags/<Namespace>.ini` per top-level namespace (23 files), each holding only its root tag.
+  `NativeTags.h/.cpp` exist and are empty until step 2 declares the first native tag.
+- **The gym is authored by `Scripts/Authoring/create_gym.py`**, not by hand: a floor, daylight and two player starts.
+  Step 3 extends the same script with the sections table.
+- `.gitattributes` routes binaries through LFS; the four asset packs are in the working tree but no pack is
+  referenced by code or a definition yet.