Platform: add script variables API and scope/policy updates

Add CRUD endpoints for script variables with validation and diff-compatible
models (ScriptEndpoints, ScriptApiModels, IScriptService, InMemoryScriptService).
Update PlatformScopes and PlatformPolicies for script.read/write permissions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Platform/StellaOps.Platform.WebService/Services/IScriptService.cs

@@ -0,0 +1,69 @@
+using StellaOps.Platform.WebService.Contracts;
+
+namespace StellaOps.Platform.WebService.Services;
+
+/// <summary>
+/// Service interface for script CRUD, versioning, and validation.
+/// </summary>
+public interface IScriptService
+{
+    Task<IReadOnlyList<ScriptSummary>> SearchAsync(
+        string tenantId,
+        ScriptLanguageDto? language,
+        ScriptVisibilityDto? visibility,
+        string? search,
+        int limit,
+        int offset,
+        CancellationToken cancellationToken = default);
+
+    Task<int> CountAsync(
+        string tenantId,
+        ScriptLanguageDto? language,
+        ScriptVisibilityDto? visibility,
+        string? search,
+        CancellationToken cancellationToken = default);
+
+    Task<ScriptDetail?> GetByIdAsync(
+        string tenantId,
+        string scriptId,
+        CancellationToken cancellationToken = default);
+
+    Task<ScriptDetail> CreateAsync(
+        string tenantId,
+        string actorId,
+        CreateScriptApiRequest request,
+        CancellationToken cancellationToken = default);
+
+    Task<ScriptDetail> UpdateAsync(
+        string tenantId,
+        string actorId,
+        string scriptId,
+        UpdateScriptApiRequest request,
+        CancellationToken cancellationToken = default);
+
+    Task<bool> DeleteAsync(
+        string tenantId,
+        string scriptId,
+        CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<ScriptVersionDto>> GetVersionsAsync(
+        string tenantId,
+        string scriptId,
+        CancellationToken cancellationToken = default);
+
+    Task<ScriptValidationResultDto> ValidateAsync(
+        ValidateScriptApiRequest request,
+        CancellationToken cancellationToken = default);
+
+    Task<ScriptVersionDetailDto?> GetVersionContentAsync(
+        string tenantId,
+        string scriptId,
+        int version,
+        CancellationToken cancellationToken = default);
+
+    Task<CompatibilityResultDto> CheckCompatibilityAsync(
+        string tenantId,
+        string scriptId,
+        CheckCompatibilityRequest request,
+        CancellationToken cancellationToken = default);
+}