Add comprehensive tests for cuddZddMisc.c achieving 97.7% line coverage

[Copilot]

Adds test coverage for src/cuddZddMisc.c to exceed the 90% target (achieved 97.7%).

Coverage Results

• Lines: 97.7% (42/43)
• Functions: 100% (4/4)

The single uncovered line (221) is a NIL(DdNode) safety check unreachable through normal API usage.

Tests Added

• Cudd_zddDagSize: constant nodes, single/multiple variables, unions, products, shared subnodes
• Cudd_zddCountMinterm: empty ZDD, single variable, unions, varying path values
• Cudd_zddPrintSubtable: empty manager, single variable, complex structures with both constant and non-constant children
• Integration: combined DagSize/CountMinterm consistency, ZDDs from ISOP

TEST_CASE("cuddZddMisc - Cudd_zddDagSize basic tests", "[cuddZddMisc]") {
    SECTION("DagSize of single variable ZDD") {
        DdManager* manager = Cudd_Init(0, 4, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0);
        DdNode* z0 = Cudd_zddIthVar(manager, 0);
        Cudd_Ref(z0);
        
        int dagSize = Cudd_zddDagSize(z0);
        REQUIRE(dagSize >= 1);
        
        Cudd_RecursiveDerefZdd(manager, z0);
        Cudd_Quit(manager);
    }
}

Warning

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I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Complete test cases for src/cuddZddMisc.c and target 90% coverage for the source file.

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