Say on every directory how it treats files it does not know, and check it (issue 1024, ADR 0422)

Every directory and archive resource carries `unknown`: move-out for a home folder whose program writes nothing there (the node-engine, delivered in mesh-host #117, moves the rest to ~/.local/state/mesh-moved/<module>/ with a list), module for ~/.ssh and ~/.claude, program elsewhere; `knows` keeps what a program or the operator relies on (powerlevel10k's compiled files, i3's scripts and the asus/g14 drop-ins, dunst's slack rule, betterbird's records, node-env's forge credential, issue 1033). Two shared folders are no longer declared. Each module's README says it. checks/owned holds every manifest to it; checks/sshdir stays while main's merge check runs it (issue 1035). Tests that pin a manifest follow the new key only. Reviewed in three rounds.

modules/feh/README.md

@@ -52,3 +52,9 @@ The module no longer writes a file into i3's `config.d`. Its window-manager line
 under `files/i3/` where it had one) are a contribution to `node-display-session`. The i3 module places
 them in its own configuration under a `# <module>` line, so this module depends on a window manager
 being assigned beside it.
+
+## Files it does not know
+
+Each directory or archive this module declares says how it treats a file it did not write (ADR 0422, ADR 0416).
+
+- `~/.local/share/feh/wallpapers`: holds only what this module declares; anything else is moved out by the node-engine to `~/.local/state/mesh-moved/feh/` with a list, never deleted (ADR 0422 §4).

modules/feh/module.json

@@ -35,7 +35,8 @@
       "type": "archive",
       "path": "${machine:account-home}/.local/share/feh/wallpapers",
       "owner": "${machine:account}",
-      "artifact": "wallpapers"
+      "artifact": "wallpapers",
+      "unknown": "move-out"
     },
     {
       "id": "fehbg",