Add seed script with 7 trees, markdown rendering, and dark mode docs

- Add comprehensive seed script with 7 troubleshooting decision trees
  - Tier 1: Password Reset, Outlook/Email, VPN, Printer Problems
  - Tier 2: Slow Computer, Network Connectivity
  - Tier 3: File Share Access Problems
- Add markdown rendering with react-markdown package
  - MarkdownContent component for session player and node editor
  - Preview toggle in description fields
- Update documentation to reflect dark mode is complete
- Update all progress tracking docs with recent changes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/components/ui/MarkdownContent.tsx

@@ -0,0 +1,94 @@
+import ReactMarkdown from 'react-markdown'
+import { cn } from '@/lib/utils'
+
+interface MarkdownContentProps {
+  content: string
+  className?: string
+}
+
+/**
+ * Renders markdown content with proper styling.
+ * Supports: bold, italic, lists, code blocks, headers, etc.
+ */
+export function MarkdownContent({ content, className }: MarkdownContentProps) {
+  return (
+    <div className={cn('prose prose-sm dark:prose-invert max-w-none', className)}>
+      <ReactMarkdown
+        components={{
+        // Style paragraphs
+        p: ({ children }) => (
+          <p className="mb-3 last:mb-0">{children}</p>
+        ),
+        // Style bold text
+        strong: ({ children }) => (
+          <strong className="font-semibold text-foreground">{children}</strong>
+        ),
+        // Style ordered lists
+        ol: ({ children }) => (
+          <ol className="mb-3 ml-4 list-decimal space-y-1 last:mb-0">{children}</ol>
+        ),
+        // Style unordered lists
+        ul: ({ children }) => (
+          <ul className="mb-3 ml-4 list-disc space-y-1 last:mb-0">{children}</ul>
+        ),
+        // Style list items
+        li: ({ children }) => (
+          <li className="text-muted-foreground">{children}</li>
+        ),
+        // Style inline code
+        code: ({ className, children, ...props }) => {
+          // Check if it's a code block (has language class) or inline code
+          const isBlock = className?.includes('language-')
+          if (isBlock) {
+            return (
+              <code
+                className={cn(
+                  'block rounded bg-muted p-3 font-mono text-sm overflow-x-auto',
+                  className
+                )}
+                {...props}
+              >
+                {children}
+              </code>
+            )
+          }
+          return (
+            <code
+              className="rounded bg-muted px-1.5 py-0.5 font-mono text-sm"
+              {...props}
+            >
+              {children}
+            </code>
+          )
+        },
+        // Style code blocks (pre)
+        pre: ({ children }) => (
+          <pre className="mb-3 overflow-x-auto rounded bg-muted p-0 last:mb-0">
+            {children}
+          </pre>
+        ),
+        // Style headers
+        h1: ({ children }) => (
+          <h1 className="mb-3 text-lg font-bold text-foreground">{children}</h1>
+        ),
+        h2: ({ children }) => (
+          <h2 className="mb-2 text-base font-bold text-foreground">{children}</h2>
+        ),
+        h3: ({ children }) => (
+          <h3 className="mb-2 text-sm font-bold text-foreground">{children}</h3>
+        ),
+        // Style horizontal rules
+        hr: () => <hr className="my-4 border-border" />,
+        // Style blockquotes
+        blockquote: ({ children }) => (
+          <blockquote className="mb-3 border-l-4 border-primary/50 pl-4 italic text-muted-foreground last:mb-0">
+            {children}
+          </blockquote>
+        ),
+      }}
+      >
+        {content}
+      </ReactMarkdown>
+    </div>
+  )
+}