Verbatim port of Fastway-Server's TFWEventBus from fw_plugin_host.pas
per feedback_copy_dont_reinterpret.md. Adjustments limited to:
- Type renames (TFW* -> T*).
- uses clause: drop fw_log; add log.types from fpc-log so the
optional Logger property uses the canonical ecosystem-wide
TLogProc shape, matching every other fpc-* library.
- Per-handler exception logging now calls Logger with
Level=llError, Category='events', and includes the source
plugin (ASourcePlugin parameter) in the message text so the
canonical signature stays meaningful.
Behaviours preserved verbatim: APluginName bulk-Unsubscribe key,
wildcard '*' subscriber, OnBroadcast external-listener tap,
snapshot-iterate-outside-lock pattern, per-handler exception
isolation, TCriticalSection.
docs/DEVELOPER_GUIDE.md added covering threading, payload
ownership, recursive Fire, OnBroadcast, logger plumbing, and
the relationship between fpc-events (ecosystem-wide pub/sub)
and per-library typed observer callbacks (bp.events / cm.events
pattern).
Tests: 44 assertions across 14 scenarios pass on x86_64-linux.
Pre-tag -vh audit on src/ev.bus.pas reports zero hints/warnings.
Ken Johnson
128ddcb4df