fix(ticket-083): bound large comparison graphs

TODO.md

@@ -6,8 +6,9 @@
   acceptance criteria to their governed source ticket. Current state:
   `IN_PROGRESS / PUBLICATION`.
 - [ ] [`ticket-083`](project/ticket-083/README.md) — keep workspace comparison
-  artifacts and caches outside analysed repository state. Current state:
-  `IN_PROGRESS / PUBLICATION`.
+  artifacts bounded and outside analysed repository state; live `PLF-8091`
+  showed a generated Platform graph above the generic JSON ceiling. Current
+  state: `IN_PROGRESS / PUBLICATION`.
 - [ ] [`ticket-084`](project/ticket-084/README.md) — honor explicit
   deterministic NL mode in compare-workspace CLI. Current state:
   `IN_PROGRESS / PUBLICATION`.

src/comparison/workspace.ts

@@ -23,6 +23,13 @@ export const WORKSPACE_COMPARISON_DEADLINE_POLICY = Object.freeze({
   maximumDeadlineMs: 40 * 60 * 1000,
 });
 
+// Generated graphs are denser than their source records. Platform currently
+// produces a ~136 MiB graph, so the generic 128 MiB JSON ceiling rejects an
+// artifact that the bounded pipeline has just produced. Keep a separate,
+// explicit ceiling for the two comparison graphs instead of weakening the
+// default limit for every JSON consumer.
+export const WORKSPACE_COMPARISON_GRAPH_MAX_BYTES = 256 * 1024 * 1024;
+
 export interface WorkspaceComparisonDeadlineLoad {
   inputBytes: number;
   llmWorkUnits: number;
@@ -203,8 +210,8 @@ export async function compareWorkspaceIntent(
       throw error;
     }
     const [baseGraph, currentGraph, baseDiagnostics, currentDiagnostics] = await Promise.all([
-      readJson<IntentGraph>(baseRun.graphPath),
-      readJson<IntentGraph>(currentRun.graphPath),
+      readJson<IntentGraph>(baseRun.graphPath, WORKSPACE_COMPARISON_GRAPH_MAX_BYTES),
+      readJson<IntentGraph>(currentRun.graphPath, WORKSPACE_COMPARISON_GRAPH_MAX_BYTES),
       readJson<DiagnosticReport>(baseRun.diagnosticsPath),
       readJson<DiagnosticReport>(currentRun.diagnosticsPath),
     ]);

test/workspace.test.ts

@@ -9,13 +9,20 @@ import {
   calculateWorkspaceComparisonDeadline,
   classifyWorkspaceTrend,
   compareWorkspaceIntent,
+  WORKSPACE_COMPARISON_GRAPH_MAX_BYTES,
 } from '../src/comparison/workspace.js';
 import { pathExists, readJson } from '../src/core/io.js';
 import type { PipelineManifest } from '../src/core/types.js';
 import { makeConfig } from './helpers.js';
 
 const exec = promisify(execFile);
 
+test('workspace comparison has a bounded graph ceiling above large Platform evidence', () => {
+  const observedPlatformGraphBytes = 142_557_246;
+  assert.ok(WORKSPACE_COMPARISON_GRAPH_MAX_BYTES > observedPlatformGraphBytes);
+  assert.equal(WORKSPACE_COMPARISON_GRAPH_MAX_BYTES, 256 * 1024 * 1024);
+});
+
 test('workspace comparison deadline scales aggregate input and LLM work in bounded 2x steps', () => {
   const baseline = calculateWorkspaceComparisonDeadline({ inputBytes: 128 * 1024, llmWorkUnits: 16 });
   assert.equal(baseline.multiplier, 1);