* perf: cut review-chat time-to-first-token
The sandbox-less PR review chat paid several blocking network round-trips
before the first token on every message. Cache GitHub App installation
tokens in-process (per scope, until ~10m before expiry, above the proxy's
5m refresh window) so the chat graph factory and proxy stop re-minting one
each turn. Also drop the duplicate thread-metadata read in the commands
proxy and replace the heavy per-message get_review staleness check with a
single lightweight PR head-SHA lookup.
Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>
* fix: keep review chat alive when reseed fails
Address review: a moved PR head now triggers _build_pr_context (and thus
get_review). For an existing chat, fall back to the last seeded context on
HTTPException instead of failing the command; fresh chats still surface the
error since they have no prior context.
Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>
---------
Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>