reporter: add a log sink for reports (filename = -)

reporter: add a log sink for reports (filename = -)

Reports could only be written to files.  Folding the legacy progress log into
the reporter needs a report that emits to the log instead, so the periodic
counter/thread output keeps appearing where operators watch it.

A report whose filename is "-" is a log sink: write_report renders its tokens
as usual, then emits the result via BEESLOG at the report's level rather than
writing a file.  Add a per-report "level" key (syslog-style integer, default
LOG_INFO) and resolve "-" reports to no directory fd.  BEESLOG applies the
same category-level gate as every other log call, so a "-" report respects
log verbosity like anything else.

Assisted-by: Claude-Code:claude-opus-4-8
Signed-off-by: Zygo Blaxell <bees@furryterror.org>