Add ProtectSystem=strict, remove PermissionStartOnly.
Extract the section of postStart that needs secrets dir write
access into a separate script with full privileges.
Simplify preStart and fix dataDir quoting.
67a464d097 Mention problems with hardened kernel and NUCs in README (Jonas Nick)
7771a4c931 Refer to systemd man pages for hardening options (Jonas Nick)
a5e10a82d8 Simplify clightning preStart (Jonas Nick)
Pull request description:
CC @cypherpunk2140
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Tree-SHA512: aa726f29e499cc268b21cac8cd07617be591cfdaa89dd0495cb979ebd3e49cc01164af25924c554429a1d35d14167dea276f7d61877452b69f027143cc3eee97