A3: a JUnit case's recorded wall is capped by its shard's wall

junitCensus summed a case's JUnit test times as duration_ms; for
plan-mode-no-op's concurrent PTY tests that is 346 s inside a 176 s shard
(the "432-613 s" history). The case wall headroom shows is now
min(sum, shard elapsed), a true upper bound. Session headroom already
used the ledger's per-session clocks.

scripts/lib/paid-report.ts

@@ -304,6 +304,7 @@ export function junitCensus(manifest: PaidRunManifest, artifacts: ReportArtifact
           : failed.failureType === 'TimeoutError' ? 'timeout' : failedRecord ? failureClassOf(failedRecord) : 'assertion';
         const error = sanitizeTrialError(failedRecord?.error ?? failed?.message);
         const sessions = caseSessions(ledger, id, byCase.size === 1);
+        // A case's JUnit times sum its concurrent tests (plan-mode-no-op: 346 s in a 176 s shard), so its wall is capped by the shard's.
         const diagnosis = failed && failureClass ? trialFailureFields({ failure_class: failureClass, exit_reason: failedRecord?.exit_reason,
           error: failedRecord?.error ?? failed.message, sessions, record: failedRecord }, STALL_WINDOW_MS) : undefined;
         if (failed) census.failedShards.add(key);
@@ -318,7 +319,7 @@ export function junitCensus(manifest: PaidRunManifest, artifacts: ReportArtifact
             + `  after a repair: ${afterRepairCommand(manifest.tier, id, shardFile(key))}` } : {}) });
         census.history.push({ ...base, case: id, file: shardFile(key), kind, trial: 1, panel: { n: 1, k: 1 }, outcome: caseOutcome,
           ...(failureClass ? { failure_class: failureClass } : {}), ...(failedRecord?.exit_reason ? { exit_reason: String(failedRecord.exit_reason) } : {}),
-          ...(error && failed ? { error } : {}), ...diagnosis, ...trialSessions(sessions), duration_ms: cases.reduce((sum, tc) => sum + tc.timeMs, 0),
+          ...(error && failed ? { error } : {}), ...diagnosis, ...trialSessions(sessions), duration_ms: Math.min(cases.reduce((sum, tc) => sum + tc.timeMs, 0), outcome.elapsedMs),
           cost_usd: Math.round(mine.reduce((sum: number, r: any) => sum + (Number(r.cost_usd) || 0), 0) * 100) / 100, ...trialCostKnown(mine, sessions),
           ...(typeof mine[0]?.model === 'string' ? { model: mine[0].model } : {}), ...(cliVersion ? { cli_version: cliVersion } : {}),
           quarantined: false, execution: outcome.reused ? 'reused' : 'executed', source: 'junit' } as TrialOutcomeRecord);

test/paid-report-census.test.ts

@@ -115,6 +115,8 @@ describe('record builders attach ledger sessions and failure causes (plan 0.1/0.
       sessions: [{ key: 'pty:session#1', runner: 'pty', elapsed_ms: 16_800, budget_ms: 180_000, end: 'completed' },
         { key: 'pty:session#2', runner: 'pty', elapsed_ms: 180_050, budget_ms: 180_000, end: 'observer_timeout' }] });
     for (const record of r.history) expect(trialRecordProblemsV1(record), record.case).toEqual([]);
+    // Its five tests run concurrently: JUnit times sum to 346 s, the shard's wall is 176.5 s (lane S A2).
+    expect(noOpRecord.duration_ms).toBe(176_495);
     const plain = report('gate', dir => { failNoOp(dir); fs.rmSync(path.join(noOp(dir), 'session-ledger.jsonl')); });
     const without = plain.history.find(record => record.case === 'plan-mode-no-op');
     expect(without.failure_class).toBe(noOpRecord.failure_class);