timps v1.4.6

Build hardening (M14)

Compiler/linker defense-in-depth for the root-running network daemon, now part
of the build system (previously applied only in local builds):

-fstack-protector-strong and -D_FORTIFY_SOURCE=2 on libcs that support
them (host + thingino musl); the thingino uClibc toolchain is built
--disable-libssp with incomplete _*_chk wrappers, so it correctly gets
neither (use --libc-musl for full compiler hardening).
Full RELRO (-Wl,-z,relro -Wl,-z,now) and non-executable stack
(-Wl,-z,noexecstack), applied unconditionally (linker-only, safe under both
libcs).
Two central switches to dial it back on a stubborn toolchain: HARDEN=0
(no compiler hardening) and FORTIFY=0 (keep SSP, drop only FORTIFY).
Mirrored in both Makefile (covers make sim / direct make target) and
build.sh (the MIPS cross build), each libc-aware.

No source/behaviour change to the streamer itself — this only strengthens how
the binary is compiled and linked. See docs/M14-build-hardening.md.

Full changelog: v1.4.5...v1.4.6