* fix(agents): release embedded-attempt session lock on every exit path
The embedded run controller acquires its session write lock eagerly at
creation and released it only inside the post-run cleanup block. An
exception thrown in post-prompt processing skipped that block, so the lock
leaked to the live gateway process until the watchdog reclaimed it and
later requests to the session failed with SessionWriteLockTimeoutError.
Add an idempotent dispose() to the lock controller and call it from the
run's outer finally so the eagerly-held lock is released on every exit
path. Normal/aborted/timed-out runs still hand the lock to
acquireForCleanup first, so dispose() is a no-op then (no double release).
Fixes#86014
* fix: keep session lock teardown comment lean
* docs(changelog): note embedded session lock fix
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Co-authored-by: Peter Steinberger <steipete@gmail.com>
32ddfc22f5