Web UI: runtime console + KV session panel, with runtime/storage libs and tests (#32)

* Add web runtime console and KV sessions

* test(web): cover runtime and KV session behavior

* Fix runtime helper formatting

web/src/lib/storage.ts

@@ -0,0 +1,19 @@
+export interface StringStorage {
+  getItem(key: string): string | null
+  setItem(key: string, value: string): void
+  removeItem(key: string): void
+}
+
+export function stored(storage: Pick<StringStorage, "getItem">, key: string, fallback: string) {
+  try { return storage.getItem(key) || fallback } catch { return fallback }
+}
+
+export function persistPublicSettings(storage: StringStorage, baseUrl: string, model: string) {
+  try {
+    storage.setItem("colibri.baseUrl", baseUrl)
+    storage.setItem("colibri.model", model)
+    // API credentials intentionally remain memory-only. Remove values left by
+    // older web releases whenever public settings are persisted.
+    storage.removeItem("colibri.apiKey")
+  } catch { /* restricted storage mode */ }
+}