fix(inspect): clarify engine-view content-gate behavior

[dev-pi2pie]

Summary

Prepare the inspect engine-view UX for the v0.1.6 release by clarifying that --content-gate does not affect raw engine inspection output.

What Changed

• keep inspect --view engine as a raw WASM engine/sample/remap surface
• add a cyan Info: note on stderr when engine view is used with:
  • explicit --content-gate ...
  • an effective non-default content-gate mode coming from config or env
• emit that note once per inspect invocation, including batch runs
• keep stdout payloads unchanged for both standard and json inspect output
• update inspect help text to describe --content-gate as pipeline-policy inspection behavior
• update README and inspector schema docs so engine vs pipeline responsibilities are explicit
• mark the implementation plan complete and add the corresponding job record

Why

inspect --view engine was already intentionally raw, but the CLI accepted --content-gate ... without explaining that the flag does not affect engine-view output. That made the feature look misleading, especially when users expected gate restrictions to show up there.

This change keeps the raw engine contract intact and adds a direct CLI explanation that points users to --view pipeline for eligibility, contentGate, acceptance, and fallback diagnosis.

Testing

Passed:

• bun test test/command-inspect.test.ts test/command-config-inspect.test.ts

Coverage added/updated for:

• explicit --content-gate default on engine view
• inherited default engine view with no info note
• config-derived non-default content-gate mode on engine view
• env-derived non-default content-gate mode on engine view
• JSON output remaining on stdout while the info note stays on stderr
• batch engine runs emitting the note exactly once

Release Note

This is intended for v0.1.6.

User-facing impact:

• inspect --view engine now explains when contentGate does not apply
• docs now clearly separate raw engine inspection from pipeline policy inspection