A module's data section says what it keeps and how precious it is; the backup holder's lines,
binding stickiness, retirement on unassign and D13's conditions follow from it, so issue 273's
empty replacement is said and an unassigned module's data is remembered, not forgotten.
ADR 0214 / to-be 43: a node seat whose holder keeps nightly restore points of what every module on
the machine declares. A contribution of kind backup may name its module's own directories, filled
per module when placed. The catalogue check refuses a store provider that contributes no backup;
parsing does not, so the providers already running stay readable.
Each contribution grain was a manifest field and a renderer of its own; a module now contributes
to any seat with a kind that seat receives, the holder places it with
${contribution:<seat>:<kind>}, and the contribution depends on the seat. node-hotkeys is the
first new seat to receive (triggers); the display session receives window-manager config.
A module that needs code after waking wrote into the service manager's sleep units; it now
contributes shell code for a named moment, which derives a dependency on node-power.
Seed the eleven node seats with the verbs they start with. A provision may
have the machine's reach: a requirement for it resolves only to a provider
in the node's own set, is never pulled in, and is refused naming who could.
A shell contribution's for gains xinitrc and xresources, placed only by the
holder of node-display-server.
A module contributes environment variables, PATH entries and shell code in named slots;
the holder of the matching seat places them with ${environment:posix|systemd} and
${shell:<shell>:<slot>}. Rendered in module order with a naming line per contribution,
PATH entries added only when missing, machine facts resolved first. A variable two
modules set, or a placeholder outside its seat's holder, is refused at parse (the
catalogue check) and at composition. Filled after every other placeholder pass, so no
scanner ever reads a shell's own ${...}.
jochen
jschoubben