fix(linux): SSH on .deb and .rpm, editor and JSON hangs, crash reports

[datlechin]

• SSH on .deb and .rpm installs: SshRuntime::acquire creates the app/<id> runtime levels only Flatpak makes, 0700, one level at a time through mkdirat/openat(O_NOFOLLOW), refusing a level owned by another user. The SSH and session Docker fixtures now start from the host layout.
• Running a long script: batch starts are counted in one pass (CharCounter) instead of from byte 0 per batch. A 100,000-statement script plans in 0.18 s; the old code was still running at 113 s.
• Show Row as JSON shortens jsonb, bytea, arrays, decimals and other long values, not just text; Copy keeps the full value. Double-click on a value over 1 MB shows a toast instead of opening an editor.
• Crash report: a panic on the GTK thread also writes the message, location, backtrace and build info to $XDG_STATE_HOME/<dir>/crashes/crash-<UTC>-<pid>.txt (0600). The next launch shows a toast with Show Report; the newest 20 reports are kept.
• An editor run keeps at most 100,000 rows across all its results; the banner names the limit.
• The Enter Password button sets its action name after its target, which removes the GTK warning on the connect-failed page.
• New user-facing strings; po/tablepro.pot follows from the Translations job.