fix startup command whitespace preservation

[ooiuuii]

Why

Custom startup commands lose shell-significant whitespace before launch. A harmless printf ending in backslash-plus-space prints a trailing space when executed directly, but Hive's real PTY prints a backslash because the resolver/parser trim the payload.

Forward the original string through the worker resolver, parser and ordinary orchestrator path. Keep trimming only for empty-input checks and CLI/preset identification; shell flags, argument augmentation, permissions and recovery policies are unchanged.

Testing

• Real loopback HTTP, temporary SQLite and native PTY cover both worker and orchestrator launches, exact output bytes and stored argv.
• Baseline: four failures, including both native launch paths; fixed: 27 passed.
• Product-only revert reproduced the same failures; restore passed.
• Focused launch/parser/route suites: 46 passed.
• After two test-only review refinements: 18 affected tests passed, final pnpm check and git diff --check passed. Product files were unchanged by those refinements; the earlier pnpm build passed.
• Blank worker commands retain HTTP 201/stopped behavior, no launch/run, and agent_start.ok=false.
• A Windows parser unit checks exact padded payload forwarding. Native Windows execution is unverified; POSIX integration cases skip there.
• Full suite was not run under the repository's risk-based guidance.
• Initial default-pnpm launcher failure occurred before tests and is not target RED; validation used the already-installed pinned toolchain. Existing orchestrator tests logged EROFS on temporary Claude trust-file writes. No permission change or retry was made; those warnings are not attributed to this patch.

The old parser assertion now expects the original padded command instead of normalized text, matching the corrected execution contract.

Self-Review

Four independent scoped reviews: architecture A, correctness A-, test quality B+ improved to A-, spec alignment A. No blocking product finding.

Accepted test findings were fixed: cleanup now attempts every server close and restores environment/fixtures in finally while surfacing failures; a Windows padded-payload unit was added. Reviewer C rechecked only those changes. Other source reviews remain applicable because product hashes did not change. Aggregate A-. Reviewers did not independently rerun runtime tests; command receipts and validation evidence are retained.