test(api): decode-fidelity, not blanket non-zero, for the client/admin list contracts

[LukasWodka]

What

Fixes the Cursor Bugbot "contract test rejects valid values" (Medium) finding on #323 — plus one same-class sibling the verification sweep surfaced.

assertProvisionedClient asserts every ProvisionedClient field decodes non-zero (a valid silent-drift check). That's right for the three hand-pinned single fixtures (create/adopt/patch), but TestContractListClientsPaginated applied it to every row of a real synced list (edge_device_list.json, reseeded by scripts/sync-backend-fixtures.sh). Per client.go, status==0 is STATUS_OFFLINE and cluster_id is "Empty on legacy / not-yet-backfilled clients" — both legitimate. So the next re-sync of a list containing an offline or unanchored row would fail CI even though decoding is correct.

Fix

New assertDecodesFrom, used per-row by the list test, catches both silent-drift directions while tolerating legitimate zeros:

drift direction	how it's caught
struct-tag drift (a Go json: tag renamed)	wire still carries the old key with a value, struct decodes zero → value mismatch
backend rename/drop on re-sync (wire field renamed, fixture reseeded)	old key vanishes → a pure value compare reads zero on both sides, so a presence assertion on the always-present keys (id/first_name/username/namespace/status) catches it

cluster_id is presence-optional (legitimately empty); its rename stays covered by the strict single-fixture tests. status==0 is tolerated (key present, value 0). The three pinned single fixtures keep the strict non-zero helper.

Sibling (same-class, from the sweep):TestContractListClientAdmins asserted name != "" for every admin row — but name is a display name that can be legitimately blank; email is the domain-guaranteed identifier. Hardened to assert email present + wire-match and name wire-fidelity only.

Verification (mutation-proven)

• struct-tag rename of cluster_id → list test fails ✓
• backend key-rename namespace→k8s_namespace on the fixture → list test fails via presence ✓
• fixture row with status:0 & cluster_id:"" → list test passes ✓
• blank admin name → admins test passes ✓
• admin email key-rename → admins test fails ✓
• go vet, gofmt -s, goimports, file-budget clean

Once merged to develop, #323 (develop → main promotion) inherits it and Bugbot re-clears.

The presence-check design was caught by a 3-lens adversarial review of an earlier draft that value-compared all six fields — that draft silently missed the backend-rename-on-resync direction, the primary class these contract tests exist to catch.

---

Note

Low Risk
Test-only changes in contract tests; no production API or CLI behavior is modified.

Overview
List contract tests no longer require every ProvisionedClient row to decode non-zero. assertDecodesFrom compares each decoded list row to the raw fixture JSON: required keys must still be present on the wire (catches backend rename/drop on re-sync), and values must match (catches Go json tag drift). status == 0 and empty cluster_id are allowed on real synced list rows.

TestContractListClientsPaginated uses assertDecodesFrom per row (mapped to page1.Results) instead of assertProvisionedClient. Create/adopt/patch single-fixture tests still use the strict non-zero helper.

TestContractListClientAdmins now asserts email is non-empty and matches the wire, and name matches the wire only (blank display names are valid).

^{Reviewed by Cursor Bugbot for commit b8fb9c4. Bugbot is set up for automated code reviews on this repo. Configure here.}

[LukasWodka]

@BugBot run

[LukasWodka]

👋 Heads-up — Code review queue is at 47 / 30

Above the WIP limit. The team convention is to review existing PRs before opening new work.

Open PRs currently in Code review (oldest first):

• averaging-service#182 — feat(weights): averaging writes SafeTensors (TF + PyTorch) — SEC-03 §8 step 4 · author: @shujaatTracebloc · reviewer: @divyasinghds
• averaging-service#183 — docs: SafeTensors deployment-order & resume-safety runbook (epic feat(auth): logout revokes the token server-side (cli#112) #116) · author: @shujaatTracebloc · reviewer: @saadqbal
• averaging-service#184 — test(weights): shared SafeTensors golden-corpus drift guard + declare safetensors dep (SEC-03) · author: @LukasWodka · no reviewer assigned
• averaging-service#185 — test(weights): average a real SafeTensors edge + a legacy edge in one cycle — SEC-03 §8 · author: @LukasWodka · no reviewer assigned
• backend#1093 — chore(deps): bump django from 5.2.14 to 5.2.15 · author: @dependabot · no reviewer assigned
• backend#1108 — test(api): CLI response-shape contract fixtures for the 9 CLI endpoints (WS-D.2) · author: @LukasWodka · reviewer: @saadqbal
• backend#1111 — feat(download): edge weights fetch tolerates .safetensors (SEC-03 step 5c hardening) · author: @shujaatTracebloc · reviewer: @saadqbal
• backend#1112 — fix(runners): migrate deprecated trainingClasses/getTrainingPlan to snake_case (#1102) · author: @LukasWodka · reviewer: @saqlainsyed007
• backend#1114 — perf(leaderboard): serializer prefetch reads + TeamSerializer is_* in Python (#978 pt2) · author: @aptracebloc · reviewer: @saqlainsyed007
• cli#323 — main -> enhance CI workflows · author: @saadqbal · reviewer: @LukasWodka

Pull from review before opening new work. (This is a nudge from the kanban WIP check, not a block.)

[cursor]

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