Trim comments across configs and services

Shorten verbose multi-paragraph comments to essentials, and drop a
stale claim in common.nix that jupiter kept its own copy of the base
config (it now imports common.nix directly).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

services/unbound.nix

@@ -8,11 +8,9 @@
 {
   services.unbound = {
     enable = true;
-    # Do NOT point the host's resolv.conf at unbound: it listens on :5335, not
-    # :53, so that would leave the host with no working resolver until pihole
-    # binds :53 (a boot-time deadlock — can't pull images / build lists). The
-    # host resolves via networking.nameservers (upstream) instead; pihole
-    # forwards to unbound explicitly at 127.0.0.1#5335.
+    # Do NOT point resolv.conf at unbound: it listens on :5335, not :53, so
+    # that leaves the host with no resolver until pihole binds :53 — a
+    # boot-time deadlock. Host resolves via networking.nameservers instead.
     resolveLocalQueries = false;
     # NixOS manages the DNSSEC root trust anchor (unbound-anchor).
     settings.server = {