fix(test): resolve additional Zig module conflicts

- Fixed vector.zig imports (proof_of_path, soulkey, entropy)
- Added missing l1_mod imports (entropy, prekey, did) in build.zig
- Fixed mod.zig re-export imports
- Resolves duplicate argon2 compilation issue (not root cause, but unblocks tests)
- Tests: 165/167 passing (98.8% pass rate)

build.zig

@@ -272,6 +272,10 @@ pub fn build(b: *std.Build) void {
     l1_qvl_mod.addImport("l0_transport", l0_mod);
     // Also add qvl to l1_mod for re-export
     l1_mod.addImport("qvl", l1_qvl_mod);
+    // Add missing module imports for mod.zig re-exports
+    l1_mod.addImport("entropy", l1_entropy_mod);
+    l1_mod.addImport("prekey", l1_prekey_mod);
+    l1_mod.addImport("did", l1_did_mod);
     // Note: libmdbx linking removed - using stub implementation for now
     // TODO: Add real libmdbx when available on build system
 
@@ -502,6 +506,8 @@ pub fn build(b: *std.Build) void {
     l1_vector_mod.addImport("pqxdh", l1_pqxdh_mod);
     l1_vector_mod.addImport("trust_graph", l1_trust_graph_mod);
     l1_vector_mod.addImport("soulkey", l1_soulkey_mod);
+    l1_vector_mod.addImport("proof_of_path", l1_pop_mod);
+    l1_vector_mod.addImport("entropy", l1_entropy_mod);
 
     const l1_vector_tests = b.addTest(.{
         .root_module = l1_vector_mod,

core/l1-identity/mod.zig

@@ -1,15 +1,15 @@
 const std = @import("std");
 
 // Re-export Identity modules
-pub const did = @import("did.zig");
+pub const did = @import("did");
 pub const soulkey = @import("soulkey");
 pub const qvl = @import("qvl");
 // Note: qvl_ffi is intentionally NOT exported here - built as separate library
-pub const entropy = @import("entropy.zig");
+pub const entropy = @import("entropy");
 pub const crypto = @import("crypto.zig");
 pub const argon2 = @import("argon2.zig");
 pub const pqxdh = @import("pqxdh");
-pub const prekey = @import("prekey.zig");
+pub const prekey = @import("prekey");
 pub const slash = @import("slash");
 pub const trust_graph = @import("trust_graph");
 pub const proof_of_path = @import("proof_of_path");

core/l1-identity/vector.zig

@@ -18,10 +18,10 @@
 
 const std = @import("std");
 const time = @import("time");
-const proof_of_path = @import("proof_of_path.zig");
-const soulkey = @import("soulkey.zig");
-const entropy = @import("entropy.zig");
-const trust_graph = @import("trust_graph.zig");
+const proof_of_path = @import("proof_of_path");
+const soulkey = @import("soulkey");
+const entropy = @import("entropy");
+const trust_graph = @import("trust_graph");
 
 /// Vector Type (RFC-0120 S4.2)
 pub const VectorType = enum(u16) {