fed-sx-m2: Step 2a — Person/Service/Group genesis object-types

Three new DefineObject artefacts in next/genesis/object-types/ for
the canonical actor object-types per design §9.1:

- Person: human-controlled identity (display name + handle + bio)
- Service: automated / programmatic actor (bot, feed, organisation)
- Group: multi-controller actor (member-set managed via Add/Remove)

Each is a small SX form with :name / :doc / :schema, identical
shape to existing object-types (note.sx, sx-artifact.sx etc) so the
existing bootstrap:populate_registry walk picks them up without
code changes. Manifest extended (object-types: 10 -> 13, total
entries: 31 -> 34).

Tests:
- genesis_parse.sh +7 cases (head form, :name, manifest membership);
  57/57.
- Hardcoded counts bumped in bootstrap_read.sh, bootstrap_load.sh,
  bootstrap_populate.sh, bootstrap_start.sh.
- bootstrap_build.sh 12/12 (bundle CID computed dynamically).

Conformance 761/761 preserved. 211/211 across 12 Step-2-adjacent
suites.

next/genesis/manifest.sx

@@ -24,6 +24,9 @@
   :object-types ("object-types/sx-artifact.sx"
     "object-types/note.sx"
     "object-types/tombstone.sx"
+    "object-types/person.sx"
+    "object-types/service.sx"
+    "object-types/group.sx"
     "object-types/define-activity.sx"
     "object-types/define-object.sx"
     "object-types/define-projection.sx"

next/genesis/object-types/group.sx

@@ -0,0 +1,11 @@
+;; next/genesis/object-types/group.sx
+;;
+;; Per design §9.1: a Group is a multi-controller actor — typically
+;; a working group, channel, or collective whose membership is
+;; managed via Add/Remove activities. Sig-suite validation honours
+;; the current key-set rather than a single keypair.
+
+(DefineObject
+  :name "Group"
+  :doc "Multi-controller actor. :name is the group's display name; :preferredUsername is the local handle; :summary is the description; :icon is a CID or URL; :members is the current member list (managed via Add/Remove)."
+  :schema (fn (obj) (string? (-> obj :name))))

next/genesis/object-types/person.sx

@@ -0,0 +1,11 @@
+;; next/genesis/object-types/person.sx
+;;
+;; Per design §9.1: a Person is the canonical actor type for a
+;; human-controlled identity. Bootstrapped via Create{Person{...}}
+;; as the actor's first activity (see nx_kernel:bootstrap_actor/4).
+;; ActivityPub-Person-compatible.
+
+(DefineObject
+  :name "Person"
+  :doc "Human-controlled actor. :name is the display name; :preferredUsername is the local handle; :summary is the profile bio; :icon is a CID or URL."
+  :schema (fn (obj) (string? (-> obj :name))))

next/genesis/object-types/service.sx

@@ -0,0 +1,11 @@
+;; next/genesis/object-types/service.sx
+;;
+;; Per design §9.1: a Service is a non-human actor — a bot, an
+;; automated feed, an organisational publisher. Same activity
+;; surface as Person, different ActivityPub Actor type. Tooling
+;; treats a Service identically to a Person except for UX hints.
+
+(DefineObject
+  :name "Service"
+  :doc "Automated / programmatic actor. :name is the display name; :preferredUsername is the local handle; :summary is the profile bio; :icon is a CID or URL."
+  :schema (fn (obj) (string? (-> obj :name))))