Code Farm: per-plot auto-replant pause and crop-lock check; community sync and node work

Continuous Delivery could never be turned off once a crop was planted. Add a
one-shot per-plot "stop after harvest" flag (POST /game/plot/stop, Devii tool
game_plot_stop, game_plots.stop_after_harvest), cleared by the next plant,
autoreplant claim or Refactor. Autoreplant now also respects crop locks through
the shared _crop_lock predicate. Plan and measurements in happyplanting.md.

Also includes the pending community sync, node network and related work in the
tree; the full suite passed (4999) with all of it.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/api/sync/follows.py

@@ -0,0 +1,31 @@
+# retoor <retoor@molodetz.nl>
+
+from devplacepy.database import get_table
+from tests.api.sync.conftest import follow_record, seed_world, sync_ok
+
+
+def local(origin, uid):
+    return get_table("sync_links").find_one(origin=origin, kind="users", origin_uid=uid)["local_uid"]
+
+
+def test_follow_unfollow_refollow_keeps_one_row_and_has_no_side_effects(client, admin, origin):
+    seed_world(client, admin, origin)
+    notifications = get_table("notifications").count()
+    xp = get_table("users").find_one(uid=local(origin, "u1"))["xp"]
+    created = sync_ok(client, admin, "follows", origin, [follow_record("f1")])["results"][0]
+    assert created["status"] == "created"
+    sync_ok(client, admin, "follows", origin, [follow_record("f1", updated_at="2025-02-01T00:00:00Z", deleted=True)])
+    assert get_table("follows").find_one(uid=created["local_uid"])["deleted_by"] == "sync"
+    sync_ok(client, admin, "follows", origin, [follow_record("f1", updated_at="2025-03-01T00:00:00Z")])
+    assert get_table("follows").count(follower_uid=local(origin, "u2"), following_uid=local(origin, "u1")) == 1
+    assert get_table("follows").find_one(uid=created["local_uid"])["deleted_at"] is None
+    assert get_table("notifications").count() == notifications
+    assert get_table("users").find_one(uid=local(origin, "u1"))["xp"] == xp
+
+
+def test_self_follow_and_unknown_users(client, admin, origin):
+    seed_world(client, admin, origin)
+    body = sync_ok(client, admin, "follows", origin, [follow_record("f1", "u1", "u1"), follow_record("f2", "ghost", "u1"), follow_record("f3", "u2", "ghost")])
+    assert [(item["status"], item["reason"]) for item in body["results"]] == [
+        ("rejected", "self_follow"), ("deferred", "unknown_author"), ("deferred", "unknown_author"),
+    ]