fix(worker): inherit environment preloads with explicit options

[steipete]

File workers constructed with an explicit environment and execArgv: [] lost the environment's startup imports, even though Node 24.21 still applies them. This breaks startup instrumentation and hooks in worker-based applications.

Select worker environment options independently from selected CLI arguments. Explicit env or execArgv re-reads the selected environment; fully inherited workers retain the parent's startup snapshot. Preserve raw CLI arguments through nested workers, require-before-import ordering, supported restrictions before preloads, Node's inherited-option error handling, positional parsing, and required-value aliases. Bun environment preloads support both space and equals forms.

Upstream: builds on oven-sh/bun#42620 and the previously ported #40328. The upstream extension is being validated with those prerequisites. Documentation and an append-only changelog entry are included.

Validation on one direct AWS Linux c7a.8xlarge lease, using Node 24.21 as oracle:

• Initial environment matrix: 11 failures /3 passes without the fix. Later Bun preload and all eight alias regressions also fail on their preceding candidates.
• Final exact head 3486ad3f6d4604eb67834e13d1a3ba1bcf272e63: 249 Node Worker tests and 43 Web Worker tests pass, run separately; Clippy and formatting pass.
• Full OpenClaw ui/src/e2e/model-catalog-partial-refresh.real-gateway.e2e.test.ts: Node 1/1, baseline Bun 0/1, final exact-head Bun 1/1. Runs use private 0700 HOME/state/tmp with umask 022.
• Final committed branch P2 review: scoped-clean.
• Both fork lanes pass on that exact head: run 37161302135.
• Final exact-head Rust cross-target checks: 12 pass, zero failed or skipped.

The initial Clippy findings were fixed and the final run passes. Advisory mordant reports three findings in untouched bun_resolver, also present in the earlier resolver PR run. The inherited Claude issue-matching workflow failed before analysis because Anthropic auth is unconfigured; the requested independent review succeeded. No workflow or credential changes are included.

Scope: this applies supported startup options; it does not implement every Node runtime flag.