Indigo.exactMatch() result depends on molecule arguments order

**Summary**
For certain molecules, the result of the Indigo.exactMatch() method depends on the order in which the molecule arguments are passed.

**Steps to Reproduce**
1. Download the .mol file from the Attachments section below (attached as .txt; please change its extension to .mol before usage).
2. Run the following Python reproduction script:
```
from indigo import Indigo

indigo = Indigo()

mol = indigo.loadMoleculeFromFile(str('path/to/mol_file.mol'))
smiles_string = 'C1[C@@H]([C@H](O[C@H]1N2C=C(C(=O)NC2=O)F)CO)O'
smiles_mol = indigo.loadMolecule(smiles_string)

direct_match = indigo.exactMatch(mol, smiles_mol)
if direct_match is not None:
print('Direct match found.')
else:
print('Direct match not found.')

# Reversed order of arguments
opposite_match = indigo.exactMatch(smiles_mol, mol)
if opposite_match is not None:
print('Opposite match found.')
else:
print('Opposite match not found.')
```

**Actual behavior**
The result of exactMatch() differs when the order of the molecule arguments is reversed:
- indigo.exactMatch(mol_1, mol_2) results in None (no match).

- indigo.exactMatch(mol_2, mol_1) results in a correct match.

**Expected behavior**
The result of exactMatch() should be symmetric and independent of the order of the molecule arguments.

**Environment details:**
- Indigo version: 1.47.0.rc1
- Python version: 3.12.11
- OS version: Ubuntu 24.04.3 LTS running under WSL2 on Windows 11 Enterprise version 25H2

**Attachments**
.mol file to reproduce the issue (please, change extension from '.txt' to '.mol'):
[Opposite_match.txt](https://github.com/user-attachments/files/32003958/Opposite_match.txt)

Opposite_match

```

-INDIGO-09092612272D

0 0 0 0 0 0 0 0 0 0 0 V3000
M V30 BEGIN CTAB
M V30 COUNTS 19 20 0 0 0
M V30 BEGIN ATOM
M V30 1 N -1.0 -1.5 0.0 0
M V30 2 C -0.5 -2.366 0.0 0
M V30 3 C 0.5 -2.366 0.0 0
M V30 4 C 1.0 -1.5 0.0 0
M V30 5 N 0.5 -0.634 0.0 0
M V30 6 C -0.5 -0.634 0.0 0
M V30 7 O -1.0 0.232 0.0 0
M V30 8 O 2.0 -1.5 0.0 0
M V30 9 F 1.0 -3.232 0.0 0
M V30 10 C 0.294 -1.026 0.0 0 CFG=1
M V30 11 C 1.103 -0.438 0.0 0
M V30 12 C 0.794 0.513 0.0 0 CFG=1
M V30 13 C -0.206 0.513 0.0 0 CFG=2
M V30 14 O -0.515 -0.438 0.0 0
M V30 15 O 1.382 1.322 0.0 0
M V30 16 H 2.376 1.217 0.0 0
M V30 17 C -0.794 1.322 0.0 0
M V30 18 O -1.788 1.217 0.0 0
M V30 19 H -2.376 2.026 0.0 0
M V30 END ATOM
M V30 BEGIN BOND
M V30 1 1 6 1
M V30 2 1 1 2
M V30 3 2 2 3
M V30 4 1 3 4
M V30 5 1 4 5
M V30 6 1 5 6
M V30 7 2 6 7
M V30 8 2 4 8
M V30 9 1 3 9
M V30 10 1 10 14
M V30 11 1 14 13
M V30 12 1 13 12
M V30 13 1 12 11
M V30 14 1 11 10
M V30 15 1 10 1 CFG=3
M V30 16 1 12 15 CFG=1
M V30 17 1 15 16
M V30 18 1 13 17 CFG=3
M V30 19 1 17 18
M V30 20 1 18 19
M V30 END BOND
M V30 BEGIN COLLECTION
M V30 MDLV30/STEABS ATOMS=(3 10 12 13)
M V30 END COLLECTION
M V30 END CTAB
M END

```

**Additional context**
Calling layout() on the molecules prior to matching does not change the result of exactMatch().

Start by running the Python reproduction with the attached Opposite_match.mol file and compare both Indigo.exactMatch() argument orders. Trace the exactMatch entry point and its molecule-matching path; done means both calls return the same correct result, with a regression check for this molecule.

Written by the indexing model from the issue text.