fix: bench refinement batch (#22-#26)

One commit per fix; merge without squashing.

• #26 (closed) Run reports skip macOS ._ files; an unreadable report costs only itself.
• #25 (closed) Source column: fixed starting width you can drag, elided, full text as tooltip.
• #22 (closed) (bench half) A device panel follows its server to the port it restarted on. The banner that never clears is plesty-lib's DevicePanel, fixed there.
• #24 (closed) The remembered fleet outranks the home default; servers running outside the open fleet are named and can be stopped; the agent follows the fleet the console loads.
• #23 (closed) A new log per start and per Clear log, relayed by the waiter and switched on request — nothing is truncated; a log tail reads at most 256 KB.

Needs a Windows check before the issues close: #23 (closed)'s relay replaces the server's own log handle, and #25 (closed) only reproduced on the installed build.