validate_bundle trusts summary.json n_total over the canonical ParamSpec, so a wrong-size theta passes

[philluiz2323]

Bug

validate_bundle in src/trinity/validate_submission.py is supposed to reject a best_theta.npy whose length does not match the canonical head size (params.make_spec().n_total, 13312). Since f56e7af ("make submission size check warning-only", #150) it no longer does:

• the summary's n_total overrides the canonical expected length (n_expected = summary_n_total), and
• a theta-length mismatch is only a warning, not an error.

So a malformed bundle passes validation as long as summary.json claims a matching (wrong) n_total — the submitter's own claim is trusted over the real spec, defeating the check.

Reproduce (offline)

from pathlib import Path; import json, numpy as np
from trinity.validate_submission import validate_bundle
d = Path("/tmp/b"); d.mkdir(exist_ok=True)
np.save(d/"best_theta.npy", np.zeros(128))               # wrong length (canonical is 13312)
(d/"summary.json").write_text(json.dumps({"n_total": 128}))  # summary claims the wrong length
print(validate_bundle(d).ok)   # -> True  (should be False)

This also leaves tests/test_validate_submission.py::test_wrong_theta_length_fails red on main (CI test-router fails for every PR).

Expected

The theta length is validated against the canonical ParamSpec.n_total (or an explicit expected_n_total override), the summary's value does not redefine it, and a mismatch is a hard error. A summary/theta disagreement stays a separate warning.

Location

src/trinity/validate_submission.py, validate_bundle (the n_total handling ~line 181 and the theta-length check ~line 195).