[FEATURE]: Plugin hooks for real-time stream observation and abort control

[marcusquinn]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Plugins currently can only observe completed text via experimental.text.complete. There is no way to monitor streaming content in real time, abort a stream mid-flight based on content rules, or retry with corrective instructions after an abort.

Proposed hooks:

• stream.delta — fires on every text-delta, reasoning-delta, and tool-input-delta event. Plugins can observe the stream and optionally set abort: true to cancel it.
• stream.aborted — fires after a stream is aborted by a delta hook. Plugins can decide whether to retry with optional corrective context injected into the conversation.

Use cases: content filtering, pattern detection, real-time monitoring, self-correcting agents.

I have a working implementation ready as a PR.

[github-actions]

This issue might be a duplicate of an existing issue. Please check:

• [FEATURE]: Plugin hooks for streaming token observation (stream.delta) and abort handling (stream.aborted) #14691: Plugin hooks for streaming token observation (stream.delta) and abort handling (stream.aborted) — same author, same proposed hooks, more detailed description

If this is intentionally a condensed re-submission, please close #14691 or reference it here so we can track the discussion in one place.

[marcusquinn]

This is an intentional re-submission with a cleaner description. The older issue #14691 is now closed, and its PR #14727 has been closed in favour of #14741 (which includes unit tests). All discussion is consolidated here.