feat: Unified Messaging System — kommunikation plugin, AI/Proactive/System participants, MessageSidebar, Rich Content Renderer

Phase 1: Backend plugin kommunikation (13 files, 10 tables, REST API, WebSocket, RBAC, DMS Bridge, Participant Registry, Mini-App Registry, Search Provider)
Phase 2: AI plugins as participants (ai_assistant + ai_proactive dock as participants, heartbeat job)
Phase 3: system_notif plugin (system events → chat messages, pinned System room)
Phase 4: Frontend MessageSidebar (replaces AISidebar, same design, comm API client, WebSocket hook, commStore)
Phase 5: Rich Content Block Renderer (11 components: Markdown, HTML, Image, Audio, Video, File, ActionCard, ContactCard, MiniApp, BlockRenderer)
BasePlugin: added services property + _container in on_activate

frontend/src/components/comm/blocks/ActionCardBlock.tsx

@@ -0,0 +1,62 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface ActionCardBlockProps {
+  block: MessageBlock;
+}
+
+interface ActionItem {
+  label: string;
+  action: string;
+  type?: 'primary' | 'secondary';
+}
+
+const ActionCardBlock: React.FC<ActionCardBlockProps> = ({ block }) => {
+  const { title, body, actions } = block.block_data;
+
+  const cardTitle: string = title || '';
+  const cardBody: string = body || '';
+  const actionList: ActionItem[] = Array.isArray(actions) ? actions : [];
+
+  const handleActionClick = (action: ActionItem) => {
+    if (action.action === 'dismiss') {
+      // Frontend handles dismiss — no-op here, parent component can wire up
+      return;
+    }
+    // Treat as URL
+    window.open(action.action, '_blank', 'noopener,noreferrer');
+  };
+
+  return (
+    <div className="border border-secondary-200 rounded-lg p-4 shadow-sm bg-white space-y-2">
+      {cardTitle && (
+        <h4 className="text-sm font-semibold text-secondary-800">{cardTitle}</h4>
+      )}
+      {cardBody && (
+        <p className="text-sm text-secondary-600">{cardBody}</p>
+      )}
+      {actionList.length > 0 && (
+        <div className="flex flex-wrap gap-2 pt-1">
+          {actionList.map((action, idx) => {
+            const isPrimary = action.type !== 'secondary';
+            return (
+              <button
+                key={idx}
+                onClick={() => handleActionClick(action)}
+                className={
+                  isPrimary
+                    ? 'px-3 py-1.5 text-sm rounded-lg bg-primary-600 text-white hover:bg-primary-700 transition-colors'
+                    : 'px-3 py-1.5 text-sm rounded-lg bg-secondary-100 text-secondary-700 hover:bg-secondary-200 transition-colors'
+                }
+              >
+                {action.label || 'Aktion'}
+              </button>
+            );
+          })}
+        </div>
+      )}
+    </div>
+  );
+};
+
+export default ActionCardBlock;

frontend/src/components/comm/blocks/AudioBlock.tsx

@@ -0,0 +1,41 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface AudioBlockProps {
+  block: MessageBlock;
+}
+
+function formatDuration(seconds: number | undefined): string | null {
+  if (typeof seconds !== 'number' || seconds <= 0) return null;
+  const mins = Math.floor(seconds / 60);
+  const secs = Math.floor(seconds % 60);
+  return `${mins}:${secs.toString().padStart(2, '0')}`;
+}
+
+const AudioBlock: React.FC<AudioBlockProps> = ({ block }) => {
+  const { url, duration } = block.block_data;
+
+  if (!url) {
+    return null;
+  }
+
+  const durationLabel = formatDuration(duration);
+
+  return (
+    <div className="space-y-1">
+      <audio
+        src={url}
+        controls
+        className="w-full rounded-lg"
+        preload="metadata"
+      />
+      {durationLabel && (
+        <p className="text-xs text-secondary-500">
+          Dauer: {durationLabel}
+        </p>
+      )}
+    </div>
+  );
+};
+
+export default AudioBlock;

frontend/src/components/comm/blocks/BlockRenderer.tsx

@@ -0,0 +1,75 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+import MarkdownBlock from './MarkdownBlock';
+import HtmlBlock from './HtmlBlock';
+import ImageBlock from './ImageBlock';
+import AudioBlock from './AudioBlock';
+import VideoBlock from './VideoBlock';
+import FileBlock from './FileBlock';
+import ActionCardBlock from './ActionCardBlock';
+import ContactCardBlock from './ContactCardBlock';
+import MiniAppBlock from './MiniAppBlock';
+
+interface BlockRendererProps {
+  blocks: MessageBlock[];
+}
+
+const BlockRenderer: React.FC<BlockRendererProps> = ({ blocks }) => {
+  if (!blocks || blocks.length === 0) {
+    return null;
+  }
+
+  // Sort blocks by sort_order to ensure correct rendering sequence
+  const sortedBlocks = [...blocks].sort((a, b) => a.sort_order - b.sort_order);
+
+  return (
+    <div className="space-y-2">
+      {sortedBlocks.map((block) => {
+        const renderBlock = (): React.ReactNode => {
+          switch (block.block_type) {
+            case 'text':
+              // Text blocks: render as plain text in a styled div
+              return (
+                <div className="text-sm whitespace-pre-wrap break-words">
+                  {block.block_data.text || block.block_data.content || ''}
+                </div>
+              );
+            case 'markdown':
+              return <MarkdownBlock block={block} />;
+            case 'html':
+              return <HtmlBlock block={block} />;
+            case 'image':
+              return <ImageBlock block={block} />;
+            case 'audio':
+              return <AudioBlock block={block} />;
+            case 'video':
+              return <VideoBlock block={block} />;
+            case 'file':
+              return <FileBlock block={block} />;
+            case 'action_card':
+              return <ActionCardBlock block={block} />;
+            case 'contact_card':
+              return <ContactCardBlock block={block} />;
+            case 'miniapp':
+              return <MiniAppBlock block={block} />;
+            default:
+              // Fallback for unknown block types
+              return (
+                <div className="text-xs text-secondary-400 italic p-2 rounded bg-secondary-50">
+                  Unbekannter Block-Typ: {block.block_type}
+                </div>
+              );
+          }
+        };
+
+        return (
+          <div key={block.id} className="block-wrapper">
+            {renderBlock()}
+          </div>
+        );
+      })}
+    </div>
+  );
+};
+
+export default BlockRenderer;

frontend/src/components/comm/blocks/ContactCardBlock.tsx

@@ -0,0 +1,52 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface ContactCardBlockProps {
+  block: MessageBlock;
+}
+
+const ContactCardBlock: React.FC<ContactCardBlockProps> = ({ block }) => {
+  const { contact_id, name } = block.block_data;
+
+  const contactName: string = name || 'Unbekannter Kontakt';
+  const contactId: string = contact_id || '';
+  const linkHref = contactId ? `/contacts/${contactId}` : '#';
+
+  // Generate initials for avatar placeholder
+  const initials = contactName
+    .split(' ')
+    .map((part) => part.charAt(0).toUpperCase())
+    .slice(0, 2)
+    .join('');
+
+  return (
+    <a
+      href={linkHref}
+      className="flex items-center gap-3 p-3 rounded-lg border border-secondary-200 bg-white shadow-sm hover:shadow-md hover:border-primary-300 transition-all"
+    >
+      <div className="flex-shrink-0 w-10 h-10 rounded-full bg-primary-100 text-primary-700 flex items-center justify-center text-sm font-semibold">
+        {initials || '?'}
+      </div>
+      <div className="flex-1 min-w-0">
+        <p className="text-sm font-medium text-secondary-700 truncate">{contactName}</p>
+        <p className="text-xs text-secondary-400">Kontakt anzeigen</p>
+      </div>
+      <svg
+        className="w-4 h-4 text-secondary-400 flex-shrink-0"
+        fill="none"
+        viewBox="0 0 24 24"
+        stroke="currentColor"
+        aria-hidden="true"
+      >
+        <path
+          strokeLinecap="round"
+          strokeLinejoin="round"
+          strokeWidth={2}
+          d="M9 5l7 7-7 7"
+        />
+      </svg>
+    </a>
+  );
+};
+
+export default ContactCardBlock;

frontend/src/components/comm/blocks/FileBlock.tsx

@@ -0,0 +1,85 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface FileBlockProps {
+  block: MessageBlock;
+}
+
+function formatFileSize(bytes: number | undefined): string {
+  if (typeof bytes !== 'number' || bytes <= 0) return '';
+  if (bytes < 1024) return `${bytes} B`;
+  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
+  if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
+  return `${(bytes / (1024 * 1024 * 1024)).toFixed(1)} GB`;
+}
+
+const fileIcon = (
+  <svg
+    className="w-8 h-8 text-secondary-400"
+    fill="none"
+    viewBox="0 0 24 24"
+    stroke="currentColor"
+    aria-hidden="true"
+  >
+    <path
+      strokeLinecap="round"
+      strokeLinejoin="round"
+      strokeWidth={1.5}
+      d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8z M14 2v6h6 M8 13h8 M8 17h5"
+    />
+  </svg>
+);
+
+const downloadIcon = (
+  <svg
+    className="w-4 h-4"
+    fill="none"
+    viewBox="0 0 24 24"
+    stroke="currentColor"
+    aria-hidden="true"
+  >
+    <path
+      strokeLinecap="round"
+      strokeLinejoin="round"
+      strokeWidth={2}
+      d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4"
+    />
+  </svg>
+);
+
+const FileBlock: React.FC<FileBlockProps> = ({ block }) => {
+  const { url, name, size } = block.block_data;
+
+  if (!url && !name) {
+    return null;
+  }
+
+  const fileName: string = name || 'Datei';
+  const fileSizeLabel = formatFileSize(size);
+
+  return (
+    <div className="flex items-center gap-3 p-3 rounded-lg border border-secondary-200 bg-white shadow-sm">
+      <div className="flex-shrink-0">{fileIcon}</div>
+      <div className="flex-1 min-w-0">
+        <p className="text-sm font-medium text-secondary-700 truncate">{fileName}</p>
+        {fileSizeLabel && (
+          <p className="text-xs text-secondary-400">{fileSizeLabel}</p>
+        )}
+      </div>
+      {url && (
+        <a
+          href={url}
+          download={fileName}
+          target="_blank"
+          rel="noopener noreferrer"
+          className="flex-shrink-0 p-2 rounded-lg bg-primary-500 text-white hover:bg-primary-600 transition-colors"
+          aria-label={`Datei herunterladen: ${fileName}`}
+        >
+          {downloadIcon}
+        </a>
+      )}
+    </div>
+  );
+};
+
+export default FileBlock;

frontend/src/components/comm/blocks/HtmlBlock.tsx

@@ -0,0 +1,45 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface HtmlBlockProps {
+  block: MessageBlock;
+}
+
+/**
+ * Basic HTML sanitization: removes <script> tags and event handler attributes.
+ * This is a minimal sanitizer — for production use DOMPurify or similar.
+ */
+function sanitizeHtml(html: string): string {
+  let sanitized = html;
+  // Remove <script>...</script> blocks (including content)
+  sanitized = sanitized.replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '');
+  // Remove <script ...> self-referencing or incomplete tags
+  sanitized = sanitized.replace(/<script\b[^>]*>/gi, '');
+  // Remove on* event handler attributes (onclick, onload, onerror, etc.)
+  sanitized = sanitized.replace(/\son\w+\s*=\s*"[^"]*"/gi, '');
+  sanitized = sanitized.replace(/\son\w+\s*=\s*'[^']*'/gi, '');
+  sanitized = sanitized.replace(/\son\w+\s*=\s*[^\s>]+/gi, '');
+  // Remove javascript: URLs in href/src
+  sanitized = sanitized.replace(/(href|src)\s*=\s*"javascript:[^"]*"/gi, '$1="#"');
+  sanitized = sanitized.replace(/(href|src)\s*=\s*'javascript:[^']*'/gi, '$1="#"');
+  return sanitized;
+}
+
+const HtmlBlock: React.FC<HtmlBlockProps> = ({ block }) => {
+  const rawHtml: string = block.block_data.html || '';
+
+  if (!rawHtml) {
+    return null;
+  }
+
+  const sanitized = sanitizeHtml(rawHtml);
+
+  return (
+    <div
+      className="prose prose-sm max-w-none text-inherit"
+      dangerouslySetInnerHTML={{ __html: sanitized }}
+    />
+  );
+};
+
+export default HtmlBlock;

frontend/src/components/comm/blocks/ImageBlock.tsx

@@ -0,0 +1,35 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface ImageBlockProps {
+  block: MessageBlock;
+}
+
+const ImageBlock: React.FC<ImageBlockProps> = ({ block }) => {
+  const { url, alt, width } = block.block_data;
+
+  if (!url) {
+    return null;
+  }
+
+  const imageAlt: string = alt || '';
+  const imageWidth: number | undefined = typeof width === 'number' ? width : undefined;
+
+  return (
+    <div className="space-y-1">
+      <a href={url} target="_blank" rel="noopener noreferrer" className="block">
+        <img
+          src={url}
+          alt={imageAlt}
+          width={imageWidth}
+          className="rounded-lg max-w-full shadow-sm cursor-pointer hover:shadow-md transition-shadow"
+        />
+      </a>
+      {imageAlt && (
+        <p className="text-xs text-secondary-500 italic">{imageAlt}</p>
+      )}
+    </div>
+  );
+};
+
+export default ImageBlock;

frontend/src/components/comm/blocks/MarkdownBlock.tsx

@@ -0,0 +1,59 @@
+import React from 'react';
+import ReactMarkdown from 'react-markdown';
+import type { MessageBlock } from '@/store/commStore';
+
+interface MarkdownBlockProps {
+  block: MessageBlock;
+}
+
+const MarkdownBlock: React.FC<MarkdownBlockProps> = ({ block }) => {
+  const markdown: string = block.block_data.markdown || block.block_data.content || '';
+
+  if (!markdown) {
+    return null;
+  }
+
+  return (
+    <div className="prose prose-sm max-w-none text-inherit">
+      <ReactMarkdown
+        components={{
+          p: ({ children }) => <p className="mb-1 last:mb-0">{children}</p>,
+          ul: ({ children }) => <ul className="list-disc pl-4 mb-1">{children}</ul>,
+          ol: ({ children }) => <ol className="list-decimal pl-4 mb-1">{children}</ol>,
+          code: ({ children, className }) => {
+            const isInline = !className;
+            if (isInline) {
+              return (
+                <code className="px-1 py-0.5 rounded bg-black/10 text-xs font-mono">
+                  {children}
+                </code>
+              );
+            }
+            return (
+              <pre className="p-2 rounded bg-black/10 overflow-x-auto">
+                <code className="text-xs font-mono">{children}</code>
+              </pre>
+            );
+          },
+          h1: ({ children }) => <h1 className="text-base font-bold mb-1">{children}</h1>,
+          h2: ({ children }) => <h2 className="text-sm font-bold mb-1">{children}</h2>,
+          h3: ({ children }) => <h3 className="text-sm font-semibold mb-1">{children}</h3>,
+          a: ({ children, href }) => (
+            <a href={href} target="_blank" rel="noopener noreferrer" className="underline">
+              {children}
+            </a>
+          ),
+          blockquote: ({ children }) => (
+            <blockquote className="border-l-2 border-current/30 pl-2 italic opacity-80">
+              {children}
+            </blockquote>
+          ),
+        }}
+      >
+        {markdown}
+      </ReactMarkdown>
+    </div>
+  );
+};
+
+export default MarkdownBlock;

frontend/src/components/comm/blocks/MiniAppBlock.tsx

@@ -0,0 +1,50 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface MiniAppBlockProps {
+  block: MessageBlock;
+}
+
+const MiniAppBlock: React.FC<MiniAppBlockProps> = ({ block }) => {
+  const { app_id, config } = block.block_data;
+
+  const appId: string = app_id || 'Unbekannt';
+  const hasConfig = config && typeof config === 'object' && Object.keys(config).length > 0;
+
+  return (
+    <div className="border-2 border-dashed border-secondary-300 rounded-lg p-4 text-center bg-secondary-50">
+      <div className="flex flex-col items-center gap-2">
+        <svg
+          className="w-8 h-8 text-secondary-400"
+          fill="none"
+          viewBox="0 0 24 24"
+          stroke="currentColor"
+          aria-hidden="true"
+        >
+          <path
+            strokeLinecap="round"
+            strokeLinejoin="round"
+            strokeWidth={1.5}
+            d="M4 6a2 2 0 012-2h12a2 2 0 012 2v12a2 2 0 01-2 2H6a2 2 0 01-2-2V6z M9 9h6v6H9z"
+          />
+        </svg>
+        <p className="text-sm font-medium text-secondary-600">
+          Mini-App: {appId}
+        </p>
+        <p className="text-xs text-secondary-400">
+          Mini-Apps werden in Zukunft vollständig gerendert.
+        </p>
+        {hasConfig && (
+          <details className="text-xs text-secondary-400 mt-1">
+            <summary className="cursor-pointer hover:text-secondary-600">Konfiguration</summary>
+            <pre className="mt-1 p-2 rounded bg-white text-left overflow-x-auto">
+              {JSON.stringify(config, null, 2)}
+            </pre>
+          </details>
+        )}
+      </div>
+    </div>
+  );
+};
+
+export default MiniAppBlock;

frontend/src/components/comm/blocks/VideoBlock.tsx

@@ -0,0 +1,30 @@
+import React from 'react';
+import type { MessageBlock } from '@/store/commStore';
+
+interface VideoBlockProps {
+  block: MessageBlock;
+}
+
+const VideoBlock: React.FC<VideoBlockProps> = ({ block }) => {
+  const { url, thumbnail } = block.block_data;
+
+  if (!url) {
+    return null;
+  }
+
+  const poster: string | undefined = typeof thumbnail === 'string' ? thumbnail : undefined;
+
+  return (
+    <div className="space-y-1">
+      <video
+        src={url}
+        controls
+        poster={poster}
+        className="w-full rounded-lg"
+        preload="metadata"
+      />
+    </div>
+  );
+};
+
+export default VideoBlock;

frontend/src/components/comm/blocks/index.ts

@@ -0,0 +1,10 @@
+export { default as BlockRenderer } from './BlockRenderer';
+export { default as MarkdownBlock } from './MarkdownBlock';
+export { default as HtmlBlock } from './HtmlBlock';
+export { default as ImageBlock } from './ImageBlock';
+export { default as AudioBlock } from './AudioBlock';
+export { default as VideoBlock } from './VideoBlock';
+export { default as FileBlock } from './FileBlock';
+export { default as ActionCardBlock } from './ActionCardBlock';
+export { default as ContactCardBlock } from './ContactCardBlock';
+export { default as MiniAppBlock } from './MiniAppBlock';

frontend/src/components/comm/blocks/test_report.md

@@ -0,0 +1,66 @@
+# Test Report: Phase 5 — Rich Content Block-Renderer
+
+## Task
+Implement Frontend Rich Content Block-Renderer Components for Unified Messaging System.
+
+## Files Created
+
+| File | Lines | Purpose |
+|------|-------|---------|
+| `BlockRenderer.tsx` | 75 | Main dispatcher — switches on `block_type`, renders appropriate sub-renderer, fallback for unknown types |
+| `MarkdownBlock.tsx` | 59 | Renders Markdown via `react-markdown` (already installed), custom component styling |
+| `HtmlBlock.tsx` | 45 | Renders sanitized HTML via `dangerouslySetInnerHTML` — strips `<script>`, `on*` handlers, `javascript:` URLs |
+| `ImageBlock.tsx` | 35 | Renders image with alt caption, optional width, opens in new tab on click |
+| `AudioBlock.tsx` | 41 | Renders `<audio>` player with controls, shows formatted duration |
+| `VideoBlock.tsx` | 30 | Renders `<video>` player with controls, optional thumbnail poster |
+| `FileBlock.tsx` | 85 | Renders file card with icon, name, size, download link |
+| `ActionCardBlock.tsx` | 62 | Renders interactive card with title, body, action buttons (primary/secondary styling) |
+| `ContactCardBlock.tsx` | 52 | Renders contact reference card with avatar initials, links to `/contacts/{id}` |
+| `MiniAppBlock.tsx` | 50 | Renders placeholder for mini-apps with app_id and config details |
+| `index.ts` | 10 | Barrel export for all components |
+
+**Total: 544 lines across 11 files**
+
+## Files Modified
+
+| File | Change |
+|------|--------|
+| `MessageSidebar.tsx` | Added `BlockRenderer` import; replaced inline block rendering (40 lines) with `<BlockRenderer blocks={msg.blocks} />` (6 lines) |
+
+## TypeScript Compilation Check
+
+```
+cd /a0/usr/workdir/leocrm-fix/frontend && npx tsc --noEmit 2>&1 | grep -E 'comm/blocks|MessageSidebar'
+→ No errors in block components or MessageSidebar
+```
+
+### Pre-existing errors (NOT introduced by this task):
+- `src/pages/Dms.tsx(553,13)`: `onRangeSelect` prop mismatch in `FileExplorerProps` — pre-existing, unrelated.
+
+## Backend Compatibility
+
+All block types match `content_types.py` definitions:
+- `text` → `block_data.text`
+- `markdown` → `block_data.markdown` (also falls back to `block_data.content`)
+- `html` → `block_data.html`
+- `image` → `block_data.url`, `block_data.alt`, `block_data.width`
+- `audio` → `block_data.url`, `block_data.duration`
+- `video` → `block_data.url`, `block_data.thumbnail`
+- `file` → `block_data.url`, `block_data.name`, `block_data.size`
+- `action_card` → `block_data.title`, `block_data.body`, `block_data.actions`
+- `contact_card` → `block_data.contact_id`, `block_data.name`
+- `miniapp` → `block_data.app_id`, `block_data.config`
+
+## Smoke Test
+
+- **TypeScript**: `npx tsc --noEmit` passes with zero new errors from block components.
+- **Import chain**: `BlockRenderer` imports all 9 sub-renderers + types from `@/store/commStore` — all resolve correctly.
+- **MessageSidebar integration**: Inline block rendering replaced with `<BlockRenderer>` component — compiles cleanly.
+- **Barrel export**: `index.ts` exports all 10 components for clean imports.
+
+## Notes
+
+- `react-markdown` was already in `package.json` (`^10.1.0`) — used directly.
+- HTML sanitization is minimal (regex-based). For production, consider `DOMPurify`.
+- Unknown block types render a fallback message ("Unbekannter Block-Typ: {type}") per spec.
+- Blocks are sorted by `sort_order` before rendering.