chore: fold the dashboard into 0.13.0

0.13.0 was prepared but never tagged, so nothing has been published
under it and its contents are still open. The dashboard therefore ships
as part of 0.13.0 rather than burning 0.14.0 and leaving a version
nobody can install.

Re-dated to the day it actually goes out, and the breaking observable
change now leads the section so an upgrader reads it first.

Author: cardmagic

CHANGELOG.md

@@ -1,7 +1,14 @@
 # Changelog
 
-## Unreleased
+## 0.13.0 - 2026-08-15
 
+- **Breaking:** make observables invalidation-only by default. An ordinary
+  `observable :status` continues to detect changes and refresh reactive
+  components, but persists `{}` and sends no scalar value over Action Cable.
+  Declare `observable :status, broadcast: :value` to deliberately store and
+  share the projection with every authorized actor subscriber. Applications
+  upgrading from 0.12.x must add that opt-in to observables rendered as scalar
+  targets.
 - Add `SolidObjects::Web`, a mountable Rack dashboard for the actor runtime.
   It covers instances and their committed state, the ready and claimed
   mailbox, reminders, effects, broadcasts, dead letters, and processes, with
@@ -30,16 +37,6 @@
 - Add `rack` as an explicit dependency at `>= 3.1`, and package the `web/`
   directory in the gem.
 
-## 0.13.0 - 2026-08-13
-
-- **Breaking:** make observables invalidation-only by default. An ordinary
-  `observable :status` continues to detect changes and refresh reactive
-  components, but persists `{}` and sends no scalar value over Action Cable.
-  Declare `observable :status, broadcast: :value` to deliberately store and
-  share the projection with every authorized actor subscriber. Applications
-  upgrading from 0.12.x must add that opt-in to observables rendered as scalar
-  targets.
-
 ## 0.12.1 - 2026-08-13
 
 - Add invalidation-only observables with `broadcast: :invalidation`. They still