Files
designcraft/apps
Gert Pellin 4f25955002 Desktop: write log records to standard error and a rotating log file
The desktop app installed no logger, so every log::warn!/log::error! in
the workspace was discarded: the crash guard's panic report, a failed
crash-recovery save, font folders that can't be read. A launch from a
desktop menu has no terminal either, so there was nothing to attach to a
bug report.

apps/designcraft/src/logging.rs (no new dependency):
- standard error plus <settings dir>/logs/designcraft.log (beside
  ui.json and prefs.json); each launch rotates the previous log to
  designcraft.1.log and .2.log, so the log of a run that crashed
  survives the next start; the file is capped at 16 MiB
- records logged before the settings directory is known are buffered
  (bounded) and written once the file is attached
- default levels: info for designcraft*, warn for everything else;
  RUST_LOG replaces them with env_logger-style directives
- never panics: an unusable directory or a failed write leaves standard
  error as the only sink

The logger is installed first in main (before the engine's panic hook)
and the file is opened after argument parsing (--version leaves no
file). The settings directory moves out of prefs_path into config_dir.
A --control or DESIGNCRAFT_CONTROL_PORT value that is not a port is now
logged instead of silently leaving the control channel off. Documented
in README.md (Quick start > Logs).
2026-10-08 11:36:29 +02:00
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