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/api/client.ts

@@ -0,0 +1,90 @@
+/**
+ * API Client for Mosaic Stack
+ * Handles authenticated requests to the backend API
+ */
+
+const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL || "http://localhost:3001";
+
+export interface ApiError {
+  code: string;
+  message: string;
+  details?: unknown;
+}
+
+export interface ApiResponse<T> {
+  data: T;
+  meta?: {
+    total?: number;
+    page?: number;
+    limit?: number;
+  };
+}
+
+/**
+ * Make an authenticated API request
+ */
+export async function apiRequest<T>(
+  endpoint: string,
+  options: RequestInit = {}
+): Promise<T> {
+  const url = `${API_BASE_URL}${endpoint}`;
+
+  const response = await fetch(url, {
+    ...options,
+    headers: {
+      "Content-Type": "application/json",
+      ...options.headers,
+    },
+    credentials: "include", // Include cookies for session
+  });
+
+  if (!response.ok) {
+    const error: ApiError = await response.json().catch(() => ({
+      code: "UNKNOWN_ERROR",
+      message: response.statusText || "An unknown error occurred",
+    }));
+
+    throw new Error(error.message);
+  }
+
+  return response.json();
+}
+
+/**
+ * GET request helper
+ */
+export async function apiGet<T>(endpoint: string): Promise<T> {
+  return apiRequest<T>(endpoint, { method: "GET" });
+}
+
+/**
+ * POST request helper
+ */
+export async function apiPost<T>(endpoint: string, data?: unknown): Promise<T> {
+  const options: RequestInit = {
+    method: "POST",
+  };
+
+  if (data !== undefined) {
+    options.body = JSON.stringify(data);
+  }
+
+  return apiRequest<T>(endpoint, options);
+}
+
+/**
+ * PATCH request helper
+ */
+export async function apiPatch<T>(endpoint: string, data: unknown): Promise<T> {
+  return apiRequest<T>(endpoint, {
+    method: "PATCH",
+    body: JSON.stringify(data),
+  });
+}
+
+/**
+ * DELETE request helper
+ */
+export async function apiDelete<T>(endpoint: string): Promise<T> {
+  return apiRequest<T>(endpoint, { method: "DELETE" });
+}