Add detector determinism analysis

[masa10-f]

Summary

• construct a graph-state stabilizer for each closure-expanded detector group
• report a detector as deterministic only when that stabilizer exactly equals the unsigned product of Pauli measurement axes on the detector support
• require both Pauli axes and non-identity support to match, catching residual operators outside the detector and cancellations inside it
• respect X/Y/Z input initialization and omit outputs without measurement bases from both sides of the comparison
• document the new APIs in the changelog

Why

Detector parity is deterministic when the measured Pauli product itself is a stabilizer. Comparing axes only on the stabilizer support could incorrectly accept extra measured operators outside the detector support or miss detector operators that cancel to identity.

Impact

PauliFrame.detector_stabilizers() exposes the non-identity Pauli support for each detector, and PauliFrame.detector_determinism() returns aligned exact-product determinism flags without changing Stim compilation behavior. Measurement signs are intentionally ignored.

Validation

• pytest -s -q (809 passed, 1 skipped)
• ruff check graphqomb/pauli_frame.py tests/test_pauli_frame.py
• mypy graphqomb/pauli_frame.py
• pyright graphqomb/pauli_frame.py
• git diff --check

[codecov]

Codecov Report

❌ Patch coverage is 90.24390% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.37%. Comparing base (98a4318) to head (7a56645).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #240      +/-   ##
==========================================
+ Coverage   86.36%   86.37%   +0.01%     
==========================================
  Files          31       31              
  Lines        5112     5153      +41     
  Branches      908      916       +8     
==========================================
+ Hits         4415     4451      +36     
- Misses        491      494       +3     
- Partials      206      208       +2     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 25892e284c

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Require detector records to cover stabilizer support

When the stabilizer has measured non-output support outside the closure-expanded detector group, this reports the detector as deterministic even though the emitted parity omits required records. For example, on a two-node edge with parity_check_group=[{0}], node 0 measured X and node 1 measured Z, the stabilizer is X0 Z1 so this all(...) returns true, but detector_groups()/Stim export still emits only rec[0]; the deterministic relation is rec[0] xor rec[1], while rec[0] alone is random. Please either require the stabilizer support to be included in the detector records or include the extra measured support before marking it deterministic.

Useful? React with 👍 / 👎.