feat: add badge/chip component system and timeline component

frontend/src/components/Badge.tsx

@@ -0,0 +1,123 @@
+import React from 'react';
+
+export type BadgeVariant = 'default' | 'status' | 'outline' | 'pill';
+export type BadgeColor = 'default' | 'cyan' | 'purple' | 'success' | 'warning' | 'error' | 'info';
+export type BadgeSize = 'compact' | 'default';
+
+export interface BadgeProps {
+  children: React.ReactNode;
+  variant?: BadgeVariant;
+  color?: BadgeColor;
+  size?: BadgeSize;
+  icon?: React.ReactNode;
+  className?: string;
+  style?: React.CSSProperties;
+}
+
+const colorStyles: Record<BadgeColor, { bg: string; text: string; border: string }> = {
+  default: {
+    bg: 'rgba(148, 163, 184, 0.1)',
+    text: 'var(--text-secondary)',
+    border: 'rgba(148, 163, 184, 0.3)',
+  },
+  cyan: {
+    bg: 'var(--accent-cyan-dim)',
+    text: 'var(--accent-cyan)',
+    border: 'rgba(0, 240, 255, 0.3)',
+  },
+  purple: {
+    bg: 'rgba(112, 0, 255, 0.1)',
+    text: '#a855f7',
+    border: 'rgba(112, 0, 255, 0.3)',
+  },
+  success: {
+    bg: 'rgba(34, 197, 94, 0.1)',
+    text: '#22c55e',
+    border: 'rgba(34, 197, 94, 0.3)',
+  },
+  warning: {
+    bg: 'rgba(245, 158, 11, 0.1)',
+    text: '#f59e0b',
+    border: 'rgba(245, 158, 11, 0.3)',
+  },
+  error: {
+    bg: 'var(--bg-error)',
+    text: 'var(--text-error)',
+    border: 'var(--border-error)',
+  },
+  info: {
+    bg: 'rgba(59, 130, 246, 0.1)',
+    text: '#3b82f6',
+    border: 'rgba(59, 130, 246, 0.3)',
+  },
+};
+
+const Badge: React.FC<BadgeProps> = ({
+  children,
+  variant = 'default',
+  color = 'default',
+  size = 'default',
+  icon,
+  className = '',
+  style,
+}) => {
+  const colors = colorStyles[color];
+  const isCompact = size === 'compact';
+
+  const baseStyles: React.CSSProperties = {
+    display: 'inline-flex',
+    alignItems: 'center',
+    gap: isCompact ? '4px' : '6px',
+    padding: isCompact ? '2px 6px' : '4px 10px',
+    fontSize: isCompact ? 'var(--text-xs)' : 'var(--text-sm)',
+    fontWeight: 600,
+    letterSpacing: '0.02em',
+    lineHeight: 1.4,
+  };
+
+  const variantStyles: Record<BadgeVariant, React.CSSProperties> = {
+    default: {
+      background: colors.bg,
+      color: colors.text,
+      border: `1px solid ${colors.border}`,
+      borderRadius: '6px',
+    },
+    status: {
+      background: colors.bg,
+      color: colors.text,
+      border: `1px solid ${colors.border}`,
+      borderRadius: '6px',
+      textTransform: 'uppercase',
+      letterSpacing: '0.05em',
+      fontSize: 'var(--text-xs)',
+    },
+    outline: {
+      background: 'transparent',
+      color: colors.text,
+      border: `1px solid ${colors.border}`,
+      borderRadius: '6px',
+    },
+    pill: {
+      background: colors.bg,
+      color: colors.text,
+      border: `1px solid ${colors.border}`,
+      borderRadius: '9999px',
+    },
+  };
+
+  return (
+    <span
+      className={className}
+      style={{
+        ...baseStyles,
+        ...variantStyles[variant],
+        ...style,
+      }}
+    >
+      {icon && <span style={{ display: 'flex', alignItems: 'center' }}>{icon}</span>}
+      {children}
+    </span>
+  );
+};
+
+export default Badge;

frontend/src/components/PageHeader.tsx

@@ -1,6 +1,7 @@
 import React from "react";
 import { Link } from "react-router-dom";
 import { ChevronRight } from "./icons";
+import Badge, { BadgeColor } from "./Badge";
 
 export interface Breadcrumb {
   label: string;
@@ -29,6 +30,15 @@ export interface PageHeaderProps {
   centered?: boolean;
 }
 
+const variantToColor: Record<string, BadgeColor> = {
+  default: "default",
+  cyan: "cyan",
+  purple: "purple",
+  success: "success",
+  warning: "warning",
+  error: "error",
+};
+
 const PageHeader: React.FC<PageHeaderProps> = ({
   title,
   description,
@@ -150,34 +160,13 @@ const PageHeader: React.FC<PageHeaderProps> = ({
             aria-live="polite"
           >
             {statusChips.map((chip, index) => (
-              <span
+              <Badge
                 key={index}
-                className={`tag ${chip.variant || "default"}`}
-                style={{
-                  ...(chip.variant === "success" && {
-                    background: "rgba(34, 197, 94, 0.1)",
-                    color: "#22c55e",
-                    border: "1px solid rgba(34, 197, 94, 0.3)",
-                  }),
-                  ...(chip.variant === "warning" && {
-                    background: "rgba(245, 158, 11, 0.1)",
-                    color: "#f59e0b",
-                    border: "1px solid rgba(245, 158, 11, 0.3)",
-                  }),
-                  ...(chip.variant === "error" && {
-                    background: "var(--bg-error)",
-                    color: "var(--text-error)",
-                    border: "1px solid var(--border-error)",
-                  }),
-                  ...(chip.variant === "purple" && {
-                    background: "rgba(112, 0, 255, 0.1)",
-                    color: "#a855f7",
-                    border: "1px solid rgba(112, 0, 255, 0.3)",
-                  }),
-                }}
+                variant="pill"
+                color={variantToColor[chip.variant || "default"]}
               >
                 {chip.label}
-              </span>
+              </Badge>
             ))}
           </div>
         )}