feat(gateway): opt-in cleanup of temporary progress bubbles (#21186)

When display.cleanup_progress (or display.platforms.<plat>.cleanup_progress)
is true, the gateway deletes tool-progress bubbles, long-running '⏳ Still
working...' notices, and status-callback messages after the final response
is delivered successfully. Currently effective on adapters that implement
delete_message (Telegram); silently no-ops elsewhere. Off by default.
Failed runs skip cleanup so bubbles stay as breadcrumbs.

Minimal plumbing: base.py's existing post_delivery_callback slot now chains
new registrations onto any existing callback (with per-callback exception
isolation) rather than clobbering. Stale-generation registrations are
rejected so they can't step on a fresher run's callbacks. This lets the
cleanup callback coexist with the background-review release hook already
registered on the same slot.

Co-authored-by: mrcharlesiv <Mrcharlesiv@gmail.com>

scripts/release.py

@@ -118,6 +118,8 @@ AUTHOR_MAP = {
     "heathley@Heathley-MacBook-Air.local": "heathley",
     "vlad19@gmail.com": "dandaka",
     "adamrummer@gmail.com": "cyclingwithelephants",
+    # Temporary tool-progress cleanup salvage (May 2026)
+    "Mrcharlesiv@gmail.com": "mrcharlesiv",
     "nbot@liizfq.top": "liizfq",
     "274096618+hermes-agent-dhabibi@users.noreply.github.com": "dhabibi",
     "dejie.guo@gmail.com": "JayGwod",