One access policy from content; onboarding into Kanidm as a form

Who may do what to what was five checks in five files: `qualifies` on
a page, `requires_group`/`public` on a resource, a desk's transition
allow-list, a self_transition's email check, the automation token.
They are now compiled from content on every load into one Cedar
policy set (src/access.rs), and every server entry point asks it: open
and submit a page, read a resource, move a record, fire a self
transition, read a bucket as the automation service, extend an
invite. Each decision names the rules that granted it; refusals and
every mutation are published on portal.access.decided, and
portal.access.<site>.may answers the same question for other apps
over request-reply (proven live against uhhm's content). The policy
validates against a fixed schema, so a content shape the compiler
cannot express fails instead of granting nothing. Identity is still
Kanidm's; the browser keeps is_qualified as a rendering hint only.

`invite: {group}` on an alternative of a gated page onboards a person:
src/people.rs creates the account, records the email, adds the group
and mints a one-time credential link through Kanidm's REST API with a
service-account token (KANIDM_API_TOKEN, in idm_people_on_boarding).
The result is recorded with the answer into the runtime's
portal_invites bucket and announced on portal.people.invited. Validated:
an invite needs a gated page and required name and email fields.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4jrCgLiKKHAEFuZUJjckH

src/content/handlers.rs

@@ -165,6 +165,19 @@ pub async fn automation_kv_handler(
     if expected.is_empty() || presented != expected {
         return Err((axum::http::StatusCode::UNAUTHORIZED, "unauthorized".to_string()));
     }
+    // The token authenticates the automation service; what it may read
+    // is the policy's to say, like every other principal.
+    let decision = crate::access::decide_and_publish(
+        &state.nats,
+        &state.access.load(),
+        &crate::access::Principal::Service { name: "automation".to_string() },
+        crate::access::Action::AutomationRead,
+        &crate::access::Resource::Bucket { name: bucket.clone() },
+        serde_json::json!({}),
+    );
+    if !decision.allow {
+        return Err((axum::http::StatusCode::FORBIDDEN, "not authorized".to_string()));
+    }
 
     let store = state
         .jetstream