fix(mcp): preserve tuple constraints in advertised schemas

Declare fixed tuple tails and lengths at the canonical boundary so client array validation accepts every tool. Preserve nonempty candidate constraints in managed and application comparisons. Add catalog-wide client checks and parser/schema parity coverage for both dialects and projection directions.

Fixes #3576

src/domain/javascript/javascriptApplicationVersionComparisonSchemas.ts

@@ -70,7 +70,9 @@ export const compareApplicationVersionsInputSchema = z
   })
   .superRefine(validateApplicationVersionIdentities);
 
-const candidateNodesSchema = z.tuple([nodeIdSchema]).rest(nodeIdSchema);
+const candidateNodesSchema = z
+  .tuple([nodeIdSchema], nodeIdSchema)
+  .check(z.minLength(1));
 const exactMatchSchema = z.strictObject({
   status: z.literal("matched"),
   basis: z.enum([