fix(circuits): Fix CI compilation errors and address PR feedback

zk-nullifier:
- Split nullifier.circom into template + nullifier_main.circom
- Fixes multiple main components error when batchnullifier includes nullifier

zk-merkle-proof & zk-id:
- Replace Num2Bits_strict(levels) with Num2Bits(levels)
- Remove redundant LessThan range check (Num2Bits already constrains)
- Remove unused comparators.circom import

Author: tilo-14

zk/zk-id/circuits/merkle_proof.circom

@@ -3,7 +3,6 @@ pragma circom 2.0.0;
 include "../node_modules/circomlib/circuits/poseidon.circom";
 include "../node_modules/circomlib/circuits/bitify.circom";
 include "../node_modules/circomlib/circuits/switcher.circom";
-include "../node_modules/circomlib/circuits/comparators.circom";
 
 // Merkle Proof Verification Template
 // Verifies that a leaf is in a Merkle tree with a given root
@@ -13,16 +12,9 @@ template MerkleProof(levels) {
     signal input leafIndex;
     signal output root;
 
-    // Range check: leafIndex < 2^levels
-    component indexRange = LessThan(levels + 1);
-    indexRange.in[0] <== leafIndex;
-    indexRange.in[1] <== 1 << levels;
-    indexRange.out === 1;
-
     component switcher[levels];
     component hasher[levels];
-
-    component indexBits = Num2Bits_strict(levels);
+    component indexBits = Num2Bits(levels);
     indexBits.in <== leafIndex;
 
     for (var i = 0; i < levels; i++) {

zk/zk-merkle-proof/circuits/merkle_proof.circom

@@ -3,23 +3,16 @@ pragma circom 2.0.0;
 include "../node_modules/circomlib/circuits/poseidon.circom";
 include "../node_modules/circomlib/circuits/bitify.circom";
 include "../node_modules/circomlib/circuits/switcher.circom";
-include "../node_modules/circomlib/circuits/comparators.circom";
 
 template MerkleProof(levels) {
     signal input leaf;
     signal input pathElements[levels];
     signal input leafIndex;
     signal output root;
 
-    // Range check: leafIndex < 2^levels
-    component indexRange = LessThan(levels + 1);
-    indexRange.in[0] <== leafIndex;
-    indexRange.in[1] <== 1 << levels;
-    indexRange.out === 1;
-
     component switcher[levels];
     component hasher[levels];
-    component indexBits = Num2Bits_strict(levels);
+    component indexBits = Num2Bits(levels);
     indexBits.in <== leafIndex;
 
     for (var i = 0; i < levels; i++) {

zk/zk-nullifier/circuits/nullifier.circom

@@ -14,4 +14,3 @@ template Nullifier() {
     nullifier === hasher.out;
 }
 
-component main { public [verification_id, nullifier] } = Nullifier();

zk/zk-nullifier/circuits/nullifier_main.circom

@@ -0,0 +1,5 @@
+pragma circom 2.0.0;
+
+include "./nullifier.circom";
+
+component main { public [verification_id, nullifier] } = Nullifier();

zk/zk-nullifier/scripts/setup.sh

@@ -60,7 +60,7 @@ echo ""
 
 # Single nullifier circuit
 echo -e "${BLUE}[5/9]${NC} Compiling nullifier.circom..."
-circom circuits/nullifier.circom \
+circom circuits/nullifier_main.circom \
     --r1cs --wasm --sym -o build
 echo -e "${GREEN}✓${NC} Single circuit compiled"
 echo ""