Unified logging: rsyslog as the system logger, the ForgeFIRM log tree

rsyslog replaces busybox syslogd/klogd (VIRTUAL-RUNTIME_base-utils-syslog,
trimmed PACKAGECONFIG) and becomes the only log writer: the appended
/etc/rsyslog.conf sets the inputs and the ff_line format and includes
the per-logger rules that `forgectrl --render-syslog` renders from the
machine settings at boot. forgefirm-logrotate becomes forgefirm-logging:
render before rsyslog starts (S19), sweep the pre-syslog log files into
/data/forgefirm/legacy-logs once, and rotate the tree at boot and hourly
by rename + HUP instead of copytruncate. Pins bumped to the pushed
forgectrl (syslog emitter, Logs tab, export), grblHAL-glowforge (syslog
emitter) and python3-gfhardware apps (syslog handlers, capture dir);
the CI harnesses set FFLOG_STDERR=1 so failure diagnostics keep the
controller's log lines. BRINGUP carries the bench validation checklist
(Next work item 14); this is an image change and rides the next flash.

meta-forgefirm/recipes-extended/rsyslog/rsyslog_%.bbappend

@@ -0,0 +1,12 @@
+# rsyslog is the ForgeFIRM system logger: the only log writer, one
+# directory per logger under /data/log/forgefirm. This appends the
+# ForgeFIRM /etc/rsyslog.conf (inputs, line format, and the include of
+# the per-logger rules that forgectrl renders at boot); the feature set
+# is trimmed in conf/distro/forgefirm.conf (PACKAGECONFIG:pn-rsyslog).
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
+
+do_install:append() {
+    # The stock rotation set covers /var/log files this image never
+    # writes; the ForgeFIRM tree has its own (forgefirm-logging).
+    rm -f ${D}${sysconfdir}/logrotate.d/logrotate.rsyslog
+}