Add integration tests for migration categories and execution

- Implemented MigrationCategoryTests to validate migration categorization for startup, release, seed, and data migrations.
- Added tests for edge cases, including null, empty, and whitespace migration names.
- Created StartupMigrationHostTests to verify the behavior of the migration host with real PostgreSQL instances using Testcontainers.
- Included tests for migration execution, schema creation, and handling of pending release migrations.
- Added SQL migration files for testing: creating a test table, adding a column, a release migration, and seeding data.

.claude/settings.local.json

@@ -4,7 +4,23 @@
       "Bash(dotnet build:*)",
       "Bash(dotnet restore:*)",
       "Bash(chmod:*)",
-      "Bash(cat:*)"
+      "Bash(cat:*)",
+      "Bash(dotnet nuget:*)",
+      "Bash(cd /mnt/c/dev/New\\ folder/git.stella-ops.org && python3:*)",
+      "Bash(cd:*)",
+      "Bash(grep:*)",
+      "Bash(src/Cli/StellaOps.Cli/Commands/CommandHandlers.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Configuration/CliProfile.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Configuration/GlobalOptions.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Output/CliError.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Services/BackendOperationsClient.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Services/OrchestratorClient.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Services/PromotionAssembler.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Services/VexObservationsClient.cs )",
+      "Bash(src/Cli/StellaOps.Cli/Telemetry/TraceparentHttpMessageHandler.cs)",
+      "Bash(python3:*)",
+      "Bash(dotnet list:*)",
+      "WebSearch"
     ],
     "deny": [],
     "ask": []