test(web): cover file classification through diff ordering

[juliusmarminge]

The diff file classifier was exported only so tests could assert its intermediate tier labels. Make it private and consolidate those tests into a check of the public file ordering result.

The ordering test retains all 16 source, test, lockfile, snapshot, and generated-path examples. Existing dependency-ordering and cycle coverage remains.

Verification: all 15 diff ordering tests pass; web typecheck and changed-file lint/format pass.

Model: gpt-6 astra. Harness: Codex in T3 Code.

Note

Cover file classification via orderDiffFiles tests and make diffFileTier private

Tests now verify file classification by checking orderDiffFiles output instead of testing diffFileTier directly. diffFileTier is made module-private in pullRequestFileOrder.logic.ts. Existing tests are grouped under the orderDiffFiles describe block.

^{Macroscope summarized 7ab7521.}

[macroscopeapp]

Approvability

Verdict: Approved at 7ab7521

Macroscope's review found this PR approvable — This is a small, self-contained test consolidation and export-surface cleanup. It leaves file classification and ordering behavior unchanged, with no product-default, deployment, schema, or sensitive-area impact.

^{You can add or adjust custom eligibility rules. Learn more.}

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.6 KiB	13.6 KiB	−49 B (−0.4%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.0 KiB	7.0 KiB	+3 B (+0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.6 KiB	6.5 KiB	−52 B (−0.8%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	57.1 KiB	57.0 KiB	−44 B (−0.1%)	66.4 KiB	✅
Codex	Live turn messages	10	9	−1 (−10.0%)	21	✅
Claude	Total thread wire	13.6 KiB	13.5 KiB	−34 B (−0.2%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.0 KiB	7.0 KiB	−2 B (−0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.5 KiB	6.5 KiB	−32 B (−0.5%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.8 KiB	57.8 KiB	−44 B (−0.1%)	66.4 KiB	✅
Claude	Live turn messages	9	8	−1 (−11.1%)	21	✅

Baseline: 0c200c5 · PR result: 7ab7521 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 113.8 KiB
• Claude decoded thread snapshot: 114.5 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.