Refactor to Store-based architecture

- Create base Store class with private backend and protected getBackend()
- Add SettingsStore, ProviderKeysStore, SessionsStore
- Each store defines its own schema via getConfig()
- AppStorage now takes stores + backend in constructor
- Remove SessionsRepository (logic moved to SessionsStore)
- Update all consumers to use store API (storage.settings.get/set, storage.providerKeys.get/set)
- Update example app to follow new pattern: create stores, gather configs, create backend, wire
- Benefits: stores own their schema, no circular deps, cleaner separation

packages/web-ui/src/agent/transports/ProviderTransport.ts

@@ -9,14 +9,14 @@ import type { AgentRunConfig, AgentTransport } from "./types.js";
 export class ProviderTransport implements AgentTransport {
 	async *run(messages: Message[], userMessage: Message, cfg: AgentRunConfig, signal?: AbortSignal) {
 		// Get API key from storage
-		const apiKey = await getAppStorage().getProviderKey(cfg.model.provider);
+		const apiKey = await getAppStorage().providerKeys.get(cfg.model.provider);
 		if (!apiKey) {
 			throw new Error("no-api-key");
 		}
 
 		// Check if CORS proxy is enabled
-		const proxyEnabled = await getAppStorage().getSetting<boolean>("proxy.enabled");
-		const proxyUrl = await getAppStorage().getSetting<string>("proxy.url");
+		const proxyEnabled = await getAppStorage().settings.get<boolean>("proxy.enabled");
+		const proxyUrl = await getAppStorage().settings.get<string>("proxy.url");
 
 		// Clone model and modify baseUrl if proxy is enabled
 		let model = cfg.model;