continue scaffolding and refine the basic foundation

app/composables/useAppState.ts

@@ -0,0 +1,90 @@
+import type { User, Session } from 'better-auth/types';
+
+/**
+ * Central application state composable
+ * Manages navigation context and critical app-level state
+ * This is the single source of truth for "what am I viewing"
+ */
+export const useAppState = () => {
+    // Current navigation context
+    const activeAgentId = useState<string | null>('appState:activeAgentId', () => null);
+    const activeTopicId = useState<string | null>('appState:activeTopicId', () => null);
+
+    // User data
+    const user = useState<User | null>('appState:user', () => null);
+    const session = useState<Session | null>('appState:session', () => null);
+
+    // Loading states
+    const isInitializing = useState<boolean>('appState:isInitializing', () => true);
+    const generationInProgress = useState<{ generationId: string } | null>('appState:generationInProgress', () => null);
+
+    /**
+     * Set the active agent and clear the topic
+     */
+    const setActiveAgent = (agentId: string | null | undefined) => {
+        activeAgentId.value = agentId || null;
+        // Clear topic when switching agents
+        activeTopicId.value = null;
+    };
+
+    /**
+     * Set the active topic
+     */
+    const setActiveTopic = (topicId: string | null | undefined) => {
+        activeTopicId.value = topicId || null;
+    };
+
+    /**
+     * Set user session data
+     */
+    const setUser = (userData: User | null) => {
+        user.value = userData;
+    };
+
+    /**
+     * Set session
+     */
+    const setSession = (sessionData: Session | null) => {
+        session.value = sessionData;
+    };
+
+    /**
+     * Mark initialization complete
+     */
+    const markInitialized = () => {
+        isInitializing.value = false;
+    };
+
+    /**
+     * Start a generation
+     */
+    const startGeneration = (generationId: string) => {
+        generationInProgress.value = { generationId };
+    };
+
+    /**
+     * End current generation
+     */
+    const endGeneration = () => {
+        generationInProgress.value = null;
+    };
+
+    return {
+        // State
+        activeAgentId,
+        activeTopicId,
+        user,
+        session,
+        isInitializing,
+        generationInProgress,
+
+        // Actions
+        setActiveAgent,
+        setActiveTopic,
+        setUser,
+        setSession,
+        markInitialized,
+        startGeneration,
+        endGeneration
+    };
+};