GHCP — Crawl: Ex2 Build/test baseline + 1 deterministic test

## Summary
- Updated ai-track-docs/build-test.md with exact verified build and test commands
- Added Should_enumerate_all_configured_language_keys to LanguagesConfigTests.cs
- Files touched: ai-track-docs/build-test.md, backend/tests/Squidex.Domain.Apps.Core.Tests/Model/Apps/LanguagesConfigTests.cs

## Evidence
- Tests/logs/metrics:
  dotnet test ... --filter Should_enumerate_all_configured_language_keys
  → Passed! - Failed: 0, Passed: 1, Skipped: 0, Total: 1, Duration: 41 ms

## Risk & Rollback
- Risk: low
- Rollback: git revert ce4b27e192

## Track
- Level: Crawl
- Exercise: Ex2

ai-track-docs/build-test.md

@@ -1,31 +1,69 @@
 # Build & Test Reference
 
-> **Status:** Placeholder — verify commands during the Crawl phase and update.
+> **Last verified:** Crawl Exercise 2 (2026-05-29, .NET 10, macOS arm64)
 
-## Backend (ASP.NET Core)
+---
+
+## Chosen module: `Squidex.Domain.Apps.Core.Model`
+
+All commands below are run from the **`backend/`** directory unless stated otherwise.
+
+---
+
+## Backend build
 
 ```bash
-# Restore & build
 cd backend
+
+# Full solution restore + build
 dotnet restore Squidex.slnx
 dotnet build Squidex.slnx
 
-# Run unit tests
-dotnet test tests/tests.sln
+# Build only the chosen module (fast)
+dotnet build src/Squidex.Domain.Apps.Core.Model/Squidex.Domain.Apps.Core.Model.csproj
+```
+
+Expected output: `Build succeeded. 0 Warning(s) 0 Error(s)`
+
+---
+
+## Backend tests — chosen module only
+
+```bash
+cd backend
 
-# Run with coverage
-cd tests && pwsh RunCoverage.ps1
+# Run all tests in the Core model test project
+dotnet test tests/Squidex.Domain.Apps.Core.Tests/Squidex.Domain.Apps.Core.Tests.csproj
+
+# Run a single test by name filter
+dotnet test tests/Squidex.Domain.Apps.Core.Tests/Squidex.Domain.Apps.Core.Tests.csproj \
+  --filter "Should_enumerate_all_configured_language_keys"
 ```
 
+Expected output: `Passed! - Failed: 0, Passed: N, Skipped: 0`
+
+---
+
+## Backend tests — full suite
+
+```bash
+cd backend
+dotnet test tests/tests.sln
+```
+
+---
+
 ## Frontend (Angular)
 
 ```bash
 cd frontend
 npm ci
-npm run build
-npm test
+npm run build          # production build
+npm test               # Vitest unit tests (headless)
 ```
 
+---
+
 ## End-to-end (Playwright)
 
 ```bash
@@ -34,14 +72,19 @@ npm ci
 npx playwright test
 ```
 
+---
+
 ## Docker / local stack
 
 ```bash
+# Build image from repo root
 docker build -t squidex:local .
 ```
 
-## TODO — complete during Crawl
+---
+
+## TODO
 
-- [ ] Confirm env vars needed for `dotnet run`
-- [ ] Add any seed-data or migration steps
-- [ ] Note CI pipeline entry points
+- [ ] Document env vars needed for `dotnet run` (MongoDB connection string etc.)
+- [ ] Add seed-data / migration steps for local dev
+- [ ] Link to CI workflow files once confirmed

backend/tests/Squidex.Domain.Apps.Core.Tests/Model/Apps/LanguagesConfigTests.cs

@@ -274,4 +274,18 @@ public class LanguagesConfigTests
 
         Assert.Equal(Language.EN, config_2.Master);
     }
+
+    [Fact]
+    public void Should_enumerate_all_configured_language_keys()
+    {
+        var config =
+            LanguagesConfig.English
+                .Set(Language.DE)
+                .Set(Language.IT);
+
+        Assert.Equal(3, config.AllKeys.Count());
+        Assert.Contains((string)Language.EN, config.AllKeys);
+        Assert.Contains((string)Language.DE, config.AllKeys);
+        Assert.Contains((string)Language.IT, config.AllKeys);
+    }
 }