Safeguard for Opticks binary tree size (#141)

Stop Opticks geometry read-in if binary tree size blows up. Warn user
and suggest solution.

Solves #77

Test:
./build/src/simg4ox -g
dune_forward_geometry_2025_april_replaced_elliptical_tubes.gdml -m
esi-g4ox/run.mac

Exits with error as expected:

```Too many nodes in binary tree (more than a 100 000) built by Opticks. Likely a nested subtraction/union solid that Opticks turns into a full binary tree. Check your geometry as described in: BNLNPPS/esi-g4ox#127
simg4ox: /esi/eic-opticks/CSG/CSGImport.cc:312: CSGPrim* CSGImport::importPrim(int, const snode&): Assertion `bn < 100000' failed.
```

Fixed DUNE geometry works fine, no exit:
./build/src/simg4ox -g duneforwarddetector3.gdml -m esi-g4ox/run.mac

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Dmitri Smirnov <dmixsmi@gmail.com>

Author: 3 people

CSG/CSGImport.cc

@@ -309,12 +309,17 @@ CSGPrim* CSGImport::importPrim(int primIdx, const snode& node )
     sn::GetLVNodesComplete(nds, lvid);   // many nullptr in unbalanced deep complete binary trees
     int bn = nds.size();                 // binary nodes
 
-    // 2. count total subs for any listnodes of this lvid
+    // Check if binary tree blows up and warn user
+    LOG_IF(warning, bn > 100000)
+        << "Too many nodes in binary tree (more than a 100 000) built by Opticks. Likely a nested "
+           "subtraction/union solid that Opticks turns into a full binary tree. Check your geometry as "
+           "described in: https://github.com/BNLNPPS/esi-g4ox/issues/127";
 
-    std::vector<const sn*> lns ;
-    sn::GetLVListnodes( lns, lvid );
-    int num_sub_total = sn::GetChildTotal( lns );
+    // 2. count total subs for any listnodes of this lvid
 
+    std::vector<const sn *> lns;
+    sn::GetLVListnodes(lns, lvid);
+    int num_sub_total = sn::GetChildTotal(lns);
     int ln = lns.size();
     bool ln_expect = ln == 0 || ln == 1 ;