Diagnostics and support

Feature	Behaviour	Level	Editora reference
Message Log	Session-only history of every echo-area message with HH:mm:ss times, newest first, bounded. Opened by clicking the status message; Esc closes; Clear empties it.	MUST	ui/MessageLog, ui/MessageLogPopup
Debug Log	Captures all java.util.logging records and uncaught exceptions in memory (bounded) and mirrors them to <app>-session.log in the config folder, keeping the previous one as <app>-session.prev.log so a crash is still visible next launch. A modeless window with Refresh, Copy, Clear, Export and Report a Problem. The only way to see logs in a packaged build.	MUST	ui/DebugLog, ui/DebugLogWindow
Uncaught exception handler	Installed first thing in main; routes to the Debug Log and an echo message. Never a stack trace dialog.	MUST	DebugLog.install()
Update notification	Reads GitHub /releases/latest. Once per app session (not per window), at most once a day, a few seconds after the first frame. A newer version shows a status-bar notice and a line in About; “Check for Updates” runs it by hand. Off switch in Settings. Never downloads or installs by itself.	MUST	update/UpdateCheck, ui/UpdateCheckScheduler, ui/UpdateCoordinator
Report a Problem	Help → Report a Problem builds a report (version, OS, runtime, settings summary, recent Debug Log), redacts it (home paths, user names, tokens, hosts), shows it editable, copies it to the clipboard and opens a prefilled GitHub issue from bug_report.yml. Over about 7,500 characters the link falls back to “paste from the clipboard”. <app> --report does the same from the command line for when the app cannot start. Nothing is uploaded.	MUST	report/ProblemReport, report/Redactor, report/ReportCommand, ui/ReportProblemWindow
Doctor	A page that checks the environment (external tools, versions, permissions, paths) with a status per row and a fix or link for each failure.	SHOULD	doctor/*, ui/DoctorPane
Crash recovery	Unsaved user work is snapshotted off the FX thread and offered back after a crash.	SHOULD (apps with user documents)	recovery/RecoveryService

Clicking the status message opens the Message Log: this session's messages, newest first.

Report a Problem: a redacted, editable report that opens as a prefilled GitHub issue.

About: version, runtime, licence, links and the update status.

Doctor: each external tool with its version, or what to install.

Secrets never reach a log, a report or a config file: see Secrets stay out of files.