An unconditional re-raise sent BrowserErrors without long_term_memory (e.g.
upload_file's failure paths) into Tools.act's handle_browser_error, which
re-raises exactly those — escaping act() as an exception where callers
previously got a recoverable ActionResult(error=...).
Guard the bypass on long_term_memory being present (the exact condition
handle_browser_error formats without re-raising; short_term_memory alone
would still re-raise), and flatten plain BrowserErrors to RuntimeError as
before. Regression test covers the plain-BrowserError path through
tools.act.
Saurav Panda
782535c34f