feat(progression): json stores on a real filesystem (slice 8)

new progression.adapters project, no engine reference. Stores take a
directory path; Godot resolves user:// with GlobalizePath and passes it
in, which is what makes them testable at all - originally I'd written
this slice off as untestable.

version lives in a file envelope, not the snapshot, so the domain only
knows the current shape. A newer-build save reports Corrupt with a
reason instead of masquerading as "no save" and getting overwritten.

atomic write via temp + rename. One file per aggregate: saving a run
leaves the profile file byte-identical, asserted.

guard rail fixed - it was matching prose in doc comments, now anchored
to using-directives plus a project.assets.json check. 63 tests.

Mr. Brick Adventures.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Godot.NET.Sdk/4.6.2">
+<Project Sdk="Godot.NET.Sdk/4.7.1">
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
     <EnableDynamicLoading>true</EnableDynamicLoading>
@@ -15,9 +15,11 @@
   <ItemGroup>
     <Compile Remove="progression\**" />
     <Compile Remove="progression.tests\**" />
+    <Compile Remove="progression.adapters\**" />
   </ItemGroup>
 
   <ItemGroup>
     <ProjectReference Include="progression\Mr.BrickAdventures.Progression.csproj" />
+    <ProjectReference Include="progression.adapters\Mr.BrickAdventures.Progression.Adapters.csproj" />
   </ItemGroup>
 </Project>