chore: add changeset for VS Code extension and package extraction

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ryanbas21

.changeset/vscode-extension.md

@@ -0,0 +1,18 @@
+---
+"@wolfcola/devtools-extension": minor
+---
+
+Extract shared logic into `@wolfcola/devtools-core` and shared Elm UI into `@wolfcola/devtools-ui`. Add VS Code extension (`oidc-devtools`) for OIDC/OAuth debugging via Chrome DevTools Protocol.
+
+### New packages
+
+- **`@wolfcola/devtools-core`** — annotators, diagnosis engine, event store, and export logic extracted from the browser extension
+- **`@wolfcola/devtools-ui`** — shared Elm UI (Timeline, Flow, Learn views) compiled to JS with TypeScript port interface
+- **`oidc-devtools`** (VS Code extension) — live OIDC/OAuth2 debugging via CDP with TreeView, WebView, and diagnosis
+
+### Browser extension changes
+
+- Now imports shared logic from `@wolfcola/devtools-core` instead of bundling it inline
+- Now imports compiled Elm UI from `@wolfcola/devtools-ui` instead of compiling Elm in-tree
+- Provides chrome.storage-backed `EventStoreChromeLive` layer (replaces the old `EventStoreLive`)
+- No user-facing behavior changes