App: crash reports and a log file; Help › Report a Bug (#107)

The desktop app installs the crash reporter and a log file at start
(both in a temporary folder in --control and CI runs, #266), journals
the window's commands (background jobs included) and every control
request's method, and ends the journal on a clean exit. A start after a
crash asks: "FieldCraft closed unexpectedly", Report It… or Not Now.

Help › Report a Bug (also Tools › Help and ui.start
diagnostics.bug_report) shows exactly what the GitHub bug form will be
filled with: the version, the OS, the last error, and for a crash where
it happened. Share my session adds the replayable commands, Include the
model file the model. Open GitHub Issue opens the form in the browser
through the system's opener; files to attach are saved to
bug-reports/<time>/ and a long session goes on the clipboard. Nothing is
sent without that click and the user's submit on GitHub.

The control channel answers the new prompts (crashed: report, close;
report_bug: set, close) and ui.inspect shows the draft; it never opens
the browser.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/engine/src/cmd/file.rs

@@ -240,6 +240,7 @@ impl Session {
         opened.history = std::mem::take(&mut self.history);
         opened.limits = self.limits;
         opened.file_access = std::mem::take(&mut self.file_access);
+        opened.crash_journal = self.crash_journal;
         opened.clear_history();
         opened.mark_opened();
         *self = opened;