feat: Add web-based viewer UI for real-time memory stream (#58)

* Add viewer HTML for claude-mem with live stream and settings interface

- Implemented a responsive layout with left and right columns for observations and settings.
- Added status indicators for connection state.
- Integrated server-sent events (SSE) for real-time updates on observations and summaries.
- Created dynamic project filter dropdown based on available observations.
- Developed settings section for environment variables and worker stats.
- Included functionality to save settings and load current stats from the server.
- Enhanced UI with custom styles for better user experience.

* Remove draft implementation plan for v5.1 web UI

* feat: Implement viewer UI with sidebar, feed, and settings management

- Add main viewer template (HTML) with styling for dark mode.
- Create App component to manage state and render Header, Feed, and Sidebar.
- Implement Feed component to display observations and summaries with filtering.
- Develop Header component for project selection and connection status.
- Create ObservationCard and SummaryCard components for displaying individual items.
- Implement Sidebar for settings management and displaying worker/database stats.
- Add hooks for managing SSE connections, settings, and stats fetching.
- Define types for observations, summaries, settings, and stats.

* Enhance UI components and improve layout

- Updated padding and layout for the feed and card components in viewer.html, viewer-template.html, and viewer.html to improve visual spacing and alignment.
- Increased card margins and padding for better readability and aesthetics.
- Adjusted font sizes, weights, and line heights for card titles and subtitles to enhance text clarity and hierarchy.
- Added a new feed-content class to center the feed items and limit their maximum width.
- Modified the Header component to improve the settings icon's SVG structure for better rendering.
- Enhanced the Sidebar component by adding a close button with an SVG icon, improving user experience for closing settings.
- Updated the Sidebar component's props to include an onClose function for handling sidebar closure.

* feat: Add user prompts feature with UI integration

- Implemented a new method in SessionStore to retrieve recent user prompts.
- Updated WorkerService to fetch and broadcast user prompts to clients.
- Enhanced the Feed component to display user prompts alongside observations and summaries.
- Created a new PromptCard component for rendering individual user prompts.
- Modified useSSE hook to handle new prompt events and processing status.
- Updated viewer templates and styles to accommodate the new prompts feature.

* feat: Add project filtering and pagination for observations

- Implemented `getAllProjects` method in `SessionStore` to retrieve unique projects from the database.
- Added `/api/observations` endpoint in `WorkerService` for paginated observations fetching.
- Enhanced `App` component to manage paginated observations and integrate with the new API.
- Updated `Feed` component to support infinite scrolling and loading more observations.
- Modified `Header` to display processing status.
- Refactored `PromptCard` to remove unnecessary processing indicator.
- Introduced `usePagination` hook to handle pagination logic for observations.
- Updated `useSSE` hook to include projects in the state.
- Adjusted types to accommodate new project data.

* Refactor viewer build process and remove deprecated HTML template

- Updated build-viewer.js to copy HTML template to build output with improved logging.
- Removed src/ui/viewer.html as it is no longer needed.
- Enhanced App component to merge observations while removing duplicates using useMemo.
- Improved Feed component to utilize a ref for onLoadMore callback and adjusted infinite scroll logic.
- Updated Sidebar component to use default settings from constants and removed redundant formatting functions.
- Refactored usePagination hook to streamline loading logic and prevent concurrent requests.
- Updated useSSE hook to use centralized API endpoints and improved reconnection logic.
- Refactored useSettings and useStats hooks to utilize constants for API endpoints and timing.
- Introduced ErrorBoundary component for better error handling in the viewer.
- Centralized API endpoint paths, default settings, timing constants, and UI-related constants into dedicated files.
- Added utility functions for formatting uptime and bytes for consistent display across components.

* feat: Enhance session management and pagination for user prompts, summaries, and observations

- Added project field to user prompts in the database and API responses.
- Implemented new API endpoints for fetching summaries and prompts with pagination.
- Updated WorkerService to handle new endpoints and filter results by project.
- Modified App component to manage paginated data for prompts and summaries.
- Refactored Feed component to remove unnecessary filtering and handle combined data.
- Improved usePagination hook to support multiple data types and project filtering.
- Adjusted useSSE hook to only load projects initially, with data fetched via pagination.
- Updated types to include project information for user prompts.

* feat: add SummarySkeleton component and data utility for merging items

- Introduced SummarySkeleton component for displaying loading state in the UI.
- Implemented mergeAndDeduplicateByProject utility function to merge real-time and paginated data while removing duplicates based on project filtering.

* Enhance UI and functionality of the viewer component

- Updated sidebar transition effects to use translate3d for improved performance.
- Added a sidebar header with title and connection status indicators.
- Modified the PromptCard to display project name instead of prompt number.
- Introduced a GitHub and X (Twitter) link in the header for easy access.
- Improved styling for setting descriptions and card hover effects.
- Enhanced Sidebar component to include connection status and updated layout.

* fix: reduce timeout for worker health checks and ensure proper responsiveness

src/ui/viewer/utils/data.ts

@@ -0,0 +1,30 @@
+/**
+ * Data manipulation utility functions
+ * Used for merging and deduplicating real-time and paginated data
+ */
+
+/**
+ * Merge real-time SSE items with paginated items, removing duplicates and filtering by project
+ * @param liveItems - Items from SSE stream
+ * @param paginatedItems - Items from pagination API (already filtered by project)
+ * @param projectFilter - Current project filter (empty string = all projects)
+ * @returns Merged and deduplicated array
+ */
+export function mergeAndDeduplicateByProject<T extends { id: number; project?: string }>(
+  liveItems: T[],
+  paginatedItems: T[],
+  projectFilter: string
+): T[] {
+  // Filter SSE items by current project (pagination is already filtered)
+  const filteredLive = projectFilter
+    ? liveItems.filter(item => item.project === projectFilter)
+    : liveItems;
+
+  // Deduplicate using Set
+  const seen = new Set<number>();
+  return [...filteredLive, ...paginatedItems].filter(item => {
+    if (seen.has(item.id)) return false;
+    seen.add(item.id);
+    return true;
+  });
+}

src/ui/viewer/utils/formatters.ts

@@ -0,0 +1,37 @@
+/**
+ * Formatting utility functions
+ * Used across UI components for consistent display
+ */
+
+/**
+ * Format epoch timestamp to locale string
+ * @param epoch - Timestamp in milliseconds since epoch
+ * @returns Formatted date string
+ */
+export function formatDate(epoch: number): string {
+  return new Date(epoch).toLocaleString();
+}
+
+/**
+ * Format seconds into hours and minutes
+ * @param seconds - Uptime in seconds
+ * @returns Formatted string like "12h 34m" or "-" if no value
+ */
+export function formatUptime(seconds?: number): string {
+  if (!seconds) return '-';
+  const hours = Math.floor(seconds / 3600);
+  const minutes = Math.floor((seconds % 3600) / 60);
+  return `${hours}h ${minutes}m`;
+}
+
+/**
+ * Format bytes into human-readable size
+ * @param bytes - Size in bytes
+ * @returns Formatted string like "1.5 MB" or "-" if no value
+ */
+export function formatBytes(bytes?: number): string {
+  if (!bytes) return '-';
+  if (bytes < 1024) return bytes + ' B';
+  if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + ' KB';
+  return (bytes / (1024 * 1024)).toFixed(1) + ' MB';
+}