feat: Skip result JSON output in write_outputs

[Siel]

Summary

• stop write_outputs from creating result.json
• keep write_json available for explicit JSON exports

Pmetrics reads the CSV artifacts and does not consume this JSON file. Skipping it avoids serializing large prior, prediction, and cycle matrices after fitting.

Tests

• cargo fmt --check
• cargo test

[github-actions]

Bencher Report

Project	PMcore
Branch	skip-result-json
Testbed	mhovd-pgx

Click to view all benchmark results

Benchmark	Latency	Benchmark Result milliseconds (ms) (Result Δ%)	Upper Boundary milliseconds (ms) (Limit %)
bimodal_ke_npag	📈 view plot 🚷 view threshold	3,548.50 ms (-22.82%) Baseline: 4,597.64 ms	6,273.26 ms (56.57%)
bimodal_ke_npod	📈 view plot 🚷 view threshold	989.29 ms (-27.96%) Baseline: 1,373.24 ms	2,088.11 ms (47.38%)
bimodal_ke_postprob	📈 view plot 🚷 view threshold	403.62 ms (+4.34%) Baseline: 386.82 ms	878.09 ms (45.97%)

🐰 View full continuous benchmarking report in Bencher

[mhovd]

I don't think the JSON itself is the problem, but the fact that we are writing the full theta for each cycle - that is the real killer. But I am not opposed to these changes.

[Siel]

I agree, the change just makes writing the JSON opt-in instead of being part of the write_outputs bundle. Users can always decide if they want to write it.

…

On Fri, Aug 28, 2026 at 7:43 AM Markus Hovd ***@***.***> wrote: *mhovd* left a comment (LAPKB/PMcore#318) <#318 (comment)> I don't think the JSON itself is the problem, but the fact that we are writing the full theta for each cycle - that is the real killer. But I am not opposed to these changes. — Reply to this email directly, view it on GitHub <#318?email_source=notifications&email_token=AAHZYHX3CEON2TJLMJZMNZT5MESY5A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKNBUHEZTGOBUGEZKM4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L#issuecomment-5449338412>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAHZYHQZOLSXYX4AWOMWNDT5MESY5AVCNFSNUABFKJSXA33TNF2G64TZHM2TSNZVGMZTCNBTHNEXG43VMU5TKMRWHAYTMNBYGY22C5QC> . You are receiving this because you authored the thread.Message ID: ***@***.***>