What remains of names.go is the naming

The hosts-file writing moved to the node-names fact; what stays is the suffix
(configurable, MESH_INTERNAL_SUFFIX, defaulting to .internal which IANA reserved
for exactly this), a node's internal name, and the rule for what a node may be
called. Several things compose an internal name, and one of them writing the
suffix differently would be a name nothing answers to.

First attempt at this rewrote the file from memory and silently dropped the
configurable suffix. Restored from the original instead — deleting most of a
file is git surgery, not paraphrase.

Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx

internal/overlay/names.go

@@ -1,10 +1,8 @@
 package overlay
 
 import (
-	"fmt"
 	"os"
 	"regexp"
-	"sort"
 	"strings"
 )
 
@@ -49,53 +47,7 @@ var nodeName = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?$`)
 // InternalName is a node's name inside the mesh.
 func InternalName(node string) string { return node + "." + Suffix() }
 
-// Hosts writes the name file for one node.
-//
-// Every node in the mesh, including this one. Including itself because a machine referring to
-// itself by its mesh name should get its overlay address rather than a loopback — otherwise a
-// service that binds to the name it was given ends up unreachable from everywhere else.
-//
-// The machine's own loopback lines come first and are not the mesh's to have an opinion about,
-// but they have to be here: this file is generated whole, so anything left out is removed.
-func Hosts(nodes []Node, self string) (string, error) {
-	var b strings.Builder
-	b.WriteString("# Generated by the mesh. Do not edit — this file is replaced whenever a node\n")
-	b.WriteString("# joins or leaves, and an edit would survive until then and vanish.\n\n")
-
-	// The floor every Linux expects, and which removing would break things that have nothing to
-	// do with the mesh.
-	b.WriteString("127.0.0.1\tlocalhost\n")
-	b.WriteString("::1\t\tlocalhost ip6-localhost ip6-loopback\n")
-	if self != "" {
-		fmt.Fprintf(&b, "127.0.1.1\t%s\n", self)
-	}
-
-	named := make([]Node, 0, len(nodes))
-	for _, n := range nodes {
-		if n.Address == "" {
-			// A node with no address on the network has no name here. Writing one that resolves
-			// to nothing is worse than not writing it: a connection to an address that does not
-			// answer hangs, where a name that does not resolve fails at once and says so.
-			continue
-		}
-		if !nodeName.MatchString(n.Name) {
-			return "", fmt.Errorf(
-				"%q cannot be a mesh name: it becomes a hostname, so it is lower-case letters, "+
-					"digits and dashes", n.Name)
-		}
-		named = append(named, n)
-	}
-	sort.Slice(named, func(i, j int) bool { return named[i].Name < named[j].Name })
-
-	if len(named) > 0 {
-		fmt.Fprintf(&b, "\n# the mesh, %d node(s)\n", len(named))
-	}
-	for _, n := range named {
-		line := fmt.Sprintf("%s\t%s\t%s", n.Address, InternalName(n.Name), n.Name)
-		if n.Name == self {
-			line += "\t# this machine"
-		}
-		b.WriteString(line + "\n")
-	}
-	return b.String(), nil
-}
+// **What remains of a larger file.** The rest wrote /etc/hosts — that is the `node-names` fact now
+// (catalogue.FactsInto), computed where the graph lives instead of by a module that ran nothing.
+// The naming stays here, because several things compose a node's internal name and one of them
+// writing the suffix differently would be a name nothing answers to.