feat(ui): implement OAuth login flow and dashboard components

* Add OAuth login handling in app and UI components
* Create new components for login and dashboard pages
* Refactor sidebar and navigation structure
* Introduce types for access entries and status responses

ui/src/types.ts

@@ -0,0 +1,111 @@
+export type AccessEntry = {
+  key_id: string;
+  last_accessed_at: string;
+  last_path: string;
+  user_agent: string;
+  request_count: number;
+};
+
+export type StatusResponse = {
+  title: string;
+  description: string;
+  version: string;
+  build_date: string;
+  commit: string;
+  connected_count: number;
+  total_known: number;
+  connected_window: string;
+  oauth_enabled: boolean;
+  entries: AccessEntry[];
+};
+
+export type NavItem = {
+  id: string;
+  label: string;
+  description: string;
+  disabled?: boolean;
+};
+
+export type ShellPage = 'dashboard' | 'projects' | 'thoughts' | 'skills' | 'guardrails' | 'files';
+
+export type Project = {
+  id: string;
+  name: string;
+  description: string;
+  created_at: string;
+  last_active_at: string;
+};
+
+export type ProjectSummary = Project & {
+  thought_count: number;
+};
+
+export type ThoughtMetadata = {
+  people: string[];
+  action_items: string[];
+  dates_mentioned: string[];
+  topics: string[];
+  type: string;
+  source: string;
+  metadata_status: string;
+  metadata_error?: string;
+};
+
+export type Thought = {
+  id: string;
+  content: string;
+  metadata: ThoughtMetadata;
+  project_id?: string;
+  archived_at?: string;
+  created_at: string;
+  updated_at: string;
+};
+
+export type SearchResult = {
+  id: string;
+  content: string;
+  metadata: ThoughtMetadata;
+  similarity: number;
+  created_at: string;
+};
+
+export type AgentSkill = {
+  id: string;
+  name: string;
+  description: string;
+  content: string;
+  tags: string[];
+  created_at: string;
+  updated_at: string;
+};
+
+export type AgentGuardrail = {
+  id: string;
+  name: string;
+  description: string;
+  content: string;
+  severity: 'low' | 'medium' | 'high' | 'critical';
+  tags: string[];
+  created_at: string;
+  updated_at: string;
+};
+
+export type StoredFile = {
+  id: string;
+  thought_id?: string;
+  project_id?: string;
+  name: string;
+  media_type: string;
+  kind: string;
+  size_bytes: number;
+  sha256: string;
+  created_at: string;
+  updated_at: string;
+};
+
+export type ThoughtStats = {
+  total_count: number;
+  type_counts: Record<string, number>;
+  top_topics: { key: string; count: number }[];
+  top_people: { key: string; count: number }[];
+};