Add result validation for fundamental default example

[Gaurav890]

Summary

If merged this pull request will add deterministic result validation to the automated fundamental default User Guide example as a focused first step toward #132.

Proposed changes

• Add a recorder federate that observes all five charger-voltage and five battery-current publications without changing the tutorial federates.
• Verify the recorded sample counts, voltage profiles, battery-current decay, charge-completion times, peak fleet load, and delivered energy with pytest.
• Run the verification immediately after the example and ignore its generated JSON artifact.

Validation

• Full fundamental User Guide example suite passes.
• Focused result suite passes: 12 passed.
• Two independent recorder runs produced identical output.