feat: the changelog in the status pane, built in

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

changelog.go

@@ -0,0 +1,10 @@
+// Package lazysecrets holds what the module's root has for the app: the
+// changelog, embedded so the status pane can show it offline.
+package lazysecrets
+
+import _ "embed"
+
+// Changelog is CHANGELOG.md as of the build: every release up to it.
+//
+//go:embed CHANGELOG.md
+var Changelog string