feat(#37-41): Add domains, ideas, relationships, agents, widgets schema

Schema additions for issues #37-41:

New models:
- Domain (#37): Life domains (work, marriage, homelab, etc.)
- Idea (#38): Brain dumps with pgvector embeddings
- Relationship (#39): Generic entity linking (blocks, depends_on)
- Agent (#40): ClawdBot agent tracking with metrics
- AgentSession (#40): Conversation session tracking
- WidgetDefinition (#41): HUD widget registry
- UserLayout (#41): Per-user dashboard configuration

Updated models:
- Task, Event, Project: Added domainId foreign key
- User, Workspace: Added new relations

New enums:
- IdeaStatus: CAPTURED, PROCESSING, ACTIONABLE, ARCHIVED, DISCARDED
- RelationshipType: BLOCKS, BLOCKED_BY, DEPENDS_ON, etc.
- AgentStatus: IDLE, WORKING, WAITING, ERROR, TERMINATED
- EntityType: Added IDEA, DOMAIN

Migration: 20260129182803_add_domains_ideas_agents_widgets

apps/web/src/lib/auth/auth-context.tsx

@@ -0,0 +1,74 @@
+"use client";
+
+import {
+  createContext,
+  useContext,
+  useState,
+  useEffect,
+  useCallback,
+  type ReactNode,
+} from "react";
+import type { AuthUser, AuthSession } from "@mosaic/shared";
+import { apiGet, apiPost } from "../api/client";
+
+interface AuthContextValue {
+  user: AuthUser | null;
+  isLoading: boolean;
+  isAuthenticated: boolean;
+  signOut: () => Promise<void>;
+  refreshSession: () => Promise<void>;
+}
+
+const AuthContext = createContext<AuthContextValue | undefined>(undefined);
+
+export function AuthProvider({ children }: { children: ReactNode }) {
+  const [user, setUser] = useState<AuthUser | null>(null);
+  const [isLoading, setIsLoading] = useState(true);
+
+  const checkSession = useCallback(async () => {
+    try {
+      const session = await apiGet<AuthSession>("/auth/session");
+      setUser(session.user);
+    } catch (error) {
+      setUser(null);
+    } finally {
+      setIsLoading(false);
+    }
+  }, []);
+
+  const signOut = useCallback(async () => {
+    try {
+      await apiPost("/auth/sign-out");
+    } catch (error) {
+      console.error("Sign out error:", error);
+    } finally {
+      setUser(null);
+    }
+  }, []);
+
+  const refreshSession = useCallback(async () => {
+    await checkSession();
+  }, [checkSession]);
+
+  useEffect(() => {
+    checkSession();
+  }, [checkSession]);
+
+  const value: AuthContextValue = {
+    user,
+    isLoading,
+    isAuthenticated: user !== null,
+    signOut,
+    refreshSession,
+  };
+
+  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
+}
+
+export function useAuth(): AuthContextValue {
+  const context = useContext(AuthContext);
+  if (context === undefined) {
+    throw new Error("useAuth must be used within AuthProvider");
+  }
+  return context;
+}