Follow bar values so a dead watch speaks, date them by their reading, and widen the path check (hq ADR 0260)

A watch that died left the block silent, a removed block kept its value, and a value
frozen at its source looked fresh because its file was new. The follower now rereads a
silent value and says so, drops removed blocks, and dates each file by the reading's
own time. The path check takes /etc and /usr/local/lib in, ignores what a container sees
inside itself, and lists the five findings standing today, which may only go.

checks/paths/shared

@@ -0,0 +1,3 @@
+# Paths every program on a machine reads as the machine's own, not as a message from the module that
+# writes them (checks/paths, novox/hq ADR 0260). One per line, with why.
+/etc/hosts  # every resolver on the machine reads it; the hostname module writes it for all of them