feat: use latest MCPB schema for BUILD manifest validation

Update manifest type usage in config and packaging to strictly enforce
the latest schema version (0.3) instead of accepting any version.

Changes:
- src/shared/config.ts: Use McpbManifestLatest instead of McpbManifest
- src/types.ts: Add McpbManifestLatest type export
- test/config.test.ts: Update tests to use McpbManifestLatest

This ensures BUILD manifests are validated against the latest schema
only during packaging, preventing use of older schema versions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/types.ts

@@ -15,6 +15,7 @@ import type {
   McpbUserConfigValuesSchema,
   McpServerConfigSchema,
 } from "./schemas/latest.js";
+import type { McpbManifestSchema as McpbManifestSchemaAny } from "./schemas/any.js";
 
 export type McpServerConfig = z.infer<typeof McpServerConfigSchema>;
 
@@ -46,7 +47,22 @@ export type McpbUserConfigurationOption = z.infer<
 
 export type McpbUserConfigValues = z.infer<typeof McpbUserConfigValuesSchema>;
 
-export type McpbManifest = z.infer<typeof McpbManifestSchema>;
+/**
+ * McpbManifest type that accepts any supported manifest version (0.1, 0.2, 0.3).
+ * This is the default manifest type that should be used for maximum compatibility.
+ */
+export type McpbManifest = z.infer<typeof McpbManifestSchemaAny>;
+
+/**
+ * @deprecated Use McpbManifest instead. This alias is kept for backward compatibility.
+ */
+export type McpbManifestAny = z.infer<typeof McpbManifestSchemaAny>;
+
+/**
+ * McpbManifest type for the latest manifest version only (0.3).
+ * Use this when you specifically need the latest version.
+ */
+export type McpbManifestLatest = z.infer<typeof McpbManifestSchema>;
 
 /**
  * Information about a MCPB package signature