access: genesis of swarms from before the registry

Swarms started before the registry keep working without one; the
genesis node's options for a registry apply only to new swarms. What
tests and migration leave is noted in future-work.

Auth plan M1, bootstrap and migration (2.5).

2 files changed, 10 insertions, 14 deletions

diff --git a/docs/access.md b/docs/access.md
index b9e0296..cd11723 100644
--- a/docs/access.md
+++ b/docs/access.md
@@ -32,14 +32,11 @@ password hashes: every member reads the document).
 
 ## A new swarm
 
-Its genesis node records the first users, with the swarm ID, in its first change:
-
-* those of `--bootstrap-users`, each with everything (`[]` and `["_continuum"]`);
-* unset: the users of its `--htpasswd` with `[]`, and those of them, or of the
-  proxy's, in `--protocol-writers` with `["_continuum"]` too.
-
-A swarm nobody could manage doesn't start: with none of them with `["_continuum"]`,
-`--genesis` is refused, naming both options.
+A swarm gets a registry from its start if its genesis node is given its first users,
+`--bootstrap-users`: it records them, with the swarm ID, in its first change, each with
+everything (`[]` and `["_continuum"]`), and the other users of its `--htpasswd` with
+`[]`. Without it, the swarm has no registry, and is as swarms were before: users all
+alike (An existing swarm, below), until someone gives it one.
 
 ## At the HTTP API
 
diff --git a/docs/example.toml b/docs/example.toml
index da808ec..e48bd2c 100644
--- a/docs/example.toml
+++ b/docs/example.toml
@@ -83,14 +83,13 @@ htpasswd = "/etc/continuum/htpasswd"
 # (remake records, members, forget records), e.g. to repair a stuck remake, in a swarm
 # without a user registry. Such writes act on the whole swarm and are logged. Epoch
 # metadata and the swarm ID are never writable. With a registry its capabilities decide
-# instead (docs/access.md); on a genesis node, those of htpasswd's users named here may
-# do everything in the new swarm's registry.
+# instead (docs/access.md).
 # protocol-writers = ["alice"]
 
-# With genesis: the new swarm's first users, each may do everything, protocol data and
-# managing users included (docs/access.md). Unset, the users of htpasswd may read and
-# write the swarm's data, and those also in protocol-writers everything. A swarm nobody
-# could manage doesn't start: set this, or protocol-writers, for one of htpasswd's users.
+# With genesis: give the new swarm a user registry (docs/access.md), these its first
+# users, each may do everything, protocol data and managing users included; htpasswd's
+# other users may read and write the swarm's data. Unset, the swarm has no registry: its
+# users are all alike, and only those in protocol-writers write protocol data.
 # bootstrap-users = ["alice"]
 
 # How log lines look: text (timestamped), journal (for systemd's journal: no timestamp or