test(bundle): opt the node --check spawn out of NODE_V8_COVERAGE so the suite survives coverage.autoAttachSubprocess

[hivecommons-hive]

Test Improvement

__tests__/bundle/bundle.test.ts only — the one pushable piece of #235 that is not blocked by another open PR.

is a syntactically valid bundle with no unresolved modules runs node --check dist/index.js via spawnSync with the inherited env. Node re-injects the parent's NODE_V8_COVERAGE into any child whose env object lacks that key, and on Node 26.10 node --check aborts under it:

TypeError: WeakRef: invalid target
    at SourceMapCacheMap.set (node:internal/source_map/source_map_cache_map:68:21)
    at maybeCacheSourceMap (node:internal/source_map/source_map_cache:198:29)
    at checkSyntax (node:internal/main/check_syntax:88:3)

Today nothing sets the variable on the vitest worker, so the test passes. The moment coverage.autoAttachSubprocess: true is enabled (the vitest 5 option that makes the bundle e2e child's V8 coverage reach the report — see #235) the worker carries NODE_V8_COVERAGE and this test is the only one in the suite that fails. Destructuring the key out of process.env does not work, because Node re-adds it; an explicit empty string is the documented opt-out.

Change: spawnSync(..., { encoding: 'utf8', env: { ...process.env, NODE_V8_COVERAGE: '' } }) plus a two-line comment.

Verified on main @ c48bd6d, Node v26.10.0:

• npx vitest run --coverage → 69 files / 1447 tests pass, All files 99.83 | 98.35 | 100 | 99.82 (unchanged)
• npx vitest run --coverage --coverage.autoAttachSubprocess → 69 files / 1447 tests pass (without this change: 1 failed, the --check test)
• npx eslint __tests__/bundle/bundle.test.ts clean

Disjoint from every open hold-gated PR (#217, #219, #221, #223, #225, #227, #229, #230, #232, #234): none touch __tests__/bundle/.

Related Issue

Refs #235 (needs-human: the remaining deliverables — coverage.autoAttachSubprocess: true in vitest.config.mjs, which is occupied by #230 until it lands, and a tsc --sourceMap → ncc -s chain so dist/index.js hits remap to src/, which is a build-script change outside the quality lane — are laid out in the issue comment posted with this PR)

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Filed by quality agent (hold-gated mode). Human review required.

— hive: agent=quality backend=copilot model=claude-fable-5.1 copilot=1.0.88

[hivecommons-hive]

Important

Held for human review by the hive's ACMM level gate.

This PR was opened by the "quality" agent while Hive policy required a human checkpoint for that agent. Non-outreach agents are held at ACMM L3–L5; the outreach agent is always held because it publishes project-facing communication.

Hive will automatically remove the hold label once current policy no longer requires a level hold for "quality". If this is an outreach PR, a human must review it and remove the label.

[hivecommons-hive]

/kind cleanup

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🐝 Hive Agent: quality | Instance: hosted-available-lke648397-260827-5q9t | SHA: unknown

— hive: agent=quality backend=copilot model=claude-fable-5.1 copilot=1.0.88