[dawsontoth]

⊙ Problem

stage CI is red, and so is every PR's Verify PR run. The Configuration page's parseConfigValue relied on JSON.stringify throwing to refuse deeply nested values. Node 26 parses and stringifies 100,000 levels without throwing, so the value was accepted and the test crashed with RangeError: Maximum call stack size exceeded inside toEqual.

💡 Solution

• In index.tsx, the walk that already checks numbers now counts depth too. It refuses more than MAX_CONFIG_DEPTH (1,000) nested arrays or objects with the same "nested too deeply" message, on any engine.
• The JSON.stringify try/catch is gone, since nothing can reach it now.
• Values up to 1,000 levels still save, as before.
• Two review concerns: the walk allocates a small array per node (an admin-only dialog, not a hot path). Stringify has no fallback (JSON.parse output can only make it throw by running out of stack, which 1,000 levels does not).

🤔 The cap is Studio-only, at 1,000

central-manager accepts any value (Joi.any() in validatePatchConfiguration), so a direct API call can still store deeper values. A server-side cap would be a separate central-manager change. 1,000 is the depth #1988 already accepted and tested. A lower cap could refuse an existing value when someone edits it.

✅ Verification

• Fails on base: on Node 26.13.0 (the .nvmrc pin) the old test crashes with the RangeError. With the fix it passes.
• The test in index.test.tsx now checks .ok and .error on their own, so a regression fails an assertion instead of crashing. Removing the guard, raising the limit by one, and counting size instead of depth each fail it with an AssertionError.
• It covers arrays and objects at the limit, one past it and at 100,000, plus 5,000 shallow siblings.
• Full gate on Node 26.13.0: vitest 653 files / 7,243 tests, tsc -b and oxlint all pass. dprint check flags AdminShell.tsx and adminShellVisibility.test.ts, which are already unformatted on stage and not part of this PR. CI doesn't run dprint check.

🤖 Generated with Claude Code

Related PRs: #2065 overlaps (carries its own copy of this fix, with the same 1,000 limit; it should drop that copy when it rebases), 1 others independent

Complexity: easy

_{Review-Coverage: authored=claude; ran=cursor-composer,codex,gemini; adjudicated=domain; declined=cursor-grok,muse; urgency=fast; rounds=2; full=1 @ c13b28c}

_{Review-Attention: read ~3m (decisions: client-only-depth-cap, depth-cap-value) @ c13b28c}

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	83.76%	19117 / 22823
🔵	Statements	83.61%	20245 / 24211
🔵	Functions	79.33%	5199 / 6553
🔵	Branches	79.06%	15885 / 20092

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
src/features/admin/configuration/index.tsx	91.93%	85.71%	88.88%	94.33%	84, 87, 134-135, 156

Generated in workflow #2556 for commit c13b28c by the Vitest Coverage Report Action