docs(B01): hand off F01 and mode confirmation fixes with test evidence

docs/协作/evidence/B01-02/browser-environment.txt

@@ -0,0 +1,8 @@
+Observed during environment capability check, 2026-10-21 UTC; copied from tool output (not a successful fixture run).
+Target: local Chromium headless with explicit repository .tmp user-data-dir.
+No page loaded and no computed-style result was obtained.
+[6:6:1021/133654.542575:ERROR:third_party/crashpad/crashpad/util/file/filesystem_posix.cc:63] mkdir : No such file or directory (2)
+chrome_crashpad_handler: --database is required
+Try 'chrome_crashpad_handler --help' for more information.
+[6:6:1021/133654.579509:FATAL:chrome/browser/process_singleton_posix.cc:297] Check failed: . socket() failed: Operation not permitted (1)
+Stopped after this error. Checked-in browser runner retains the Chromium sandbox; only --build-only completed in this environment.