Standardize management payload validation (codex)

[numnx]

🧩 Task: Standardize management payload validation

Automated task PR opened by Code UX for T09.

📋 Summary

Sprint: Sprint 142 · QS: Code Quality & Performance Audit · Task: T09

Audit and improve Code UX quality and performance by tightening existing hot-path contracts across live snapshots, execution projection, provider telemetry, dashboard render derivation, repository boundaries, MCP validation, guardrails, and documentation.

📝 Full Task Prompt

## Objective
Improve MCP management API reliability by centralizing one remaining cluster of ad hoc payload parsing into `payload-parsers.ts` and covering validation errors with focused tests.

## Scope
- Edit `src/mcp/management/payload-parsers.ts`
- Edit one or more management action files with local ad hoc parsing after inspection: `src/mcp/management/task-actions.ts`, `src/mcp/management/sprint-actions.ts`, `src/mcp/management/project-actions.ts`, `src/mcp/management/settings-actions.ts`, or `src/mcp/management/memory-actions.ts`
- Edit the corresponding focused tests under `tests/backend/mcp/`, such as `tests/backend/mcp/management-task-actions.test.ts`, `tests/backend/mcp/management-project-actions.test.ts`, or `tests/backend/mcp/management-sprint-actions.test.ts`
- Update `docs/mcp/tools-and-contracts.md` if request semantics for null versus undefined are clarified

## Implementation Requirements
1. Search the listed management action files for duplicated required string, optional string, enum, number, boolean, array, or patch-value parsing that bypasses existing parser helpers.
2. Add narrowly scoped parser helpers to `payload-parsers.ts` only for repeated patterns found in real action files, preserving trim behavior and explicit `null` versus `undefined` semantics.
3. Refactor the selected action handlers to use the shared parser helpers and keep approval-envelope/error response shapes unchanged.
4. Add tests for success, missing required value, invalid enum/type, and explicit null handling for the refactored action path.

## Constraints
- Do not rename MCP tools or change public action names.
- Do not broaden the task to every management action file; refactor one coherent duplicated parsing cluster with tests.
- Preserve existing validation error wording where tests or docs depend on it, unless the new wording is more consistent and tests are updated intentionally.
- Do not change repository write behavior behind the actions.

## Verification
- Run the focused MCP management test file(s) touched, for example `pnpm exec vitest run tests/backend/mcp/management-task-actions.test.ts`.
- Run `pnpm run lint`.
- Success means the selected action path uses shared parser helpers and tests cover consistent success and validation failure envelopes.

✅ QA Review

⏳ QA review runs after this PR is opened. Check the task card in the dashboard for the outcome once it lands.

🤖 Model & Provider

Provider	Codex CLI
Model	gpt-5.5

⏱️ Timing

Started	2026-07-06 18:05:10 UTC
Finished	2026-07-06 18:09:39 UTC
Duration	4m 30s

📊 Token Usage

Metric	Value
Input tokens	109,526
Cached input tokens	806,016
Output tokens	6,043
Total tokens	921,585
Invocations	1
Tool calls	34
Active time	2m 41s

Included usage estimate (subscription/local login): $1.13

🌿 Branch Info

Base: feature/CODUX-142-qs-code-quality-performance-audit-6
Head: task/feature-codux-142-qs-code-quality-performance-au-t09-codex-mr9j5s0u

---

🤖 Generated by Code UX