Add changesets.

Author: rkistner

Diff for: .changeset/lovely-impalas-do.md

@@ -0,0 +1,5 @@
+---
+'@powersync/web': minor
+---
+
+Add cacheSizeKb option, defaulting to 50MB.

Diff for: .changeset/slow-spiders-smash.md

@@ -0,0 +1,5 @@
+---
+'@powersync/diagnostics-app': minor
+---
+
+Switch diagnostics app to OPFS.

Diff for: .changeset/spotty-students-serve.md

@@ -0,0 +1,5 @@
+---
+'@powersync/op-sqlite': minor
+---
+
+Default to using memory for temp store, and 50MB cache size.