query-seq! can leak a session/tap when the lazy seq is abandoned (A7)

[krukow]

_{Generated via Copilot on behalf of @krukow}

query-seq! can leak a session/tap when the lazy seq is abandoned

Found during the GA Phase 2 correctness/async review.

query-seq! (src/github/copilot_sdk/helpers.clj) returns a lazy sequence backed by a
live session and an event tap. The cleanup (finish! / disconnect!) only runs when the
seq is fully realized to its natural end (nil / session.idle / session.error, or
:max-events reached). If a caller abandons the seq early — e.g. (take 1 (query-seq! ...))
or (first ...) — cleanup never runs, leaking the session and its tap.

This is the inherent tension of returning a lazy sequence over a managed resource: the
consumer controls realization, but the resource needs deterministic release.

Proposed resolution (options)

• Document the foot-gun prominently on query-seq! and steer callers toward query-chan
  / query (which clean up deterministically) when they may not consume the whole seq.
• And/or provide a bounded/closeable variant (explicit close/with-open-style lifecycle,
  or a :max-events-bounded realization) so early termination still releases the session.

Severity: post-ga (no impact when the seq is consumed to completion, which is the
documented usage).