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

app/plugins/builtins/kommunikation/schemas.py

@@ -0,0 +1,177 @@
+"""Pydantic schemas for the kommunikation plugin API."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, Field
+
+
+# ─── Conversation Schemas ───
+
+class ParticipantResponse(BaseModel):
+    id: str
+    conversation_id: str
+    participant_id: str | None = None
+    participant_type: str
+    display_name: str | None = None
+    role: str
+    joined_at: str | None = None
+
+
+class ConversationCreate(BaseModel):
+    title: str | None = None
+    participant_ids: list[str] = Field(default_factory=list)
+    participant_types: list[str] = Field(default_factory=lambda: ["user"])
+    initial_message: str | None = None
+    is_direct: bool = False
+
+
+class ConversationUpdate(BaseModel):
+    title: str | None = None
+    is_archived: bool | None = None
+
+
+class ConversationResponse(BaseModel):
+    id: str
+    title: str | None = None
+    is_locked: bool = False
+    locked_by: str | None = None
+    is_direct: bool = False
+    is_archived: bool = False
+    is_pinned: bool = False
+    created_by: str | None = None
+    created_by_type: str = "user"
+    last_msg_at: str | None = None
+    last_msg_preview: str | None = None
+    last_msg_sender_type: str | None = None
+    participants: list[ParticipantResponse] = Field(default_factory=list)
+    unread_count: int = 0
+    metadata: dict[str, Any] = Field(default_factory=dict)
+
+
+class ConversationListResponse(BaseModel):
+    items: list[ConversationResponse]
+    total: int
+
+
+# ─── Participant Management ───
+
+class ParticipantAdd(BaseModel):
+    participant_id: str
+    participant_type: str = "user"
+    role: str = "member"
+
+
+class ParticipantRoleUpdate(BaseModel):
+    role: str = Field(..., pattern="^(admin|member|reader)$")
+
+
+# ─── Message Schemas ───
+
+class MessageBlockCreate(BaseModel):
+    block_type: str
+    block_data: dict[str, Any]
+
+
+class MessageBlockResponse(BaseModel):
+    id: str
+    block_type: str
+    block_data: dict[str, Any]
+    sort_order: int = 0
+
+
+class AttachmentCreate(BaseModel):
+    file_id: str | None = None
+    file_source: str = "comm"
+
+
+class AttachmentResponse(BaseModel):
+    id: str
+    file_id: str | None = None
+    file_source: str = "comm"
+    file_name: str
+    file_type: str
+    file_size: int | None = None
+    thumbnail_path: str | None = None
+
+
+class MessageCreate(BaseModel):
+    content: str = ""
+    content_format: str = "text"
+    blocks: list[MessageBlockCreate] = Field(default_factory=list)
+    reply_to_id: str | None = None
+    attachments: list[AttachmentCreate] = Field(default_factory=list)
+
+
+class MessageUpdate(BaseModel):
+    content: str | None = None
+    read: bool | None = None
+
+
+class MessageResponse(BaseModel):
+    id: str
+    conversation_id: str
+    sender_id: str | None = None
+    sender_type: str
+    content: str = ""
+    content_format: str = "text"
+    metadata: dict[str, Any] = Field(default_factory=dict)
+    reply_to_id: str | None = None
+    is_pinned: bool = False
+    created_at: str | None = None
+    edited_at: str | None = None
+    blocks: list[MessageBlockResponse] = Field(default_factory=list)
+    attachments: list[AttachmentResponse] = Field(default_factory=list)
+    reactions: list[dict[str, Any]] = Field(default_factory=list)
+
+
+class MessageListResponse(BaseModel):
+    items: list[MessageResponse]
+    total: int
+    page: int = 1
+    has_more: bool = False
+
+
+# ─── Reaction Schemas ───
+
+class ReactionCreate(BaseModel):
+    emoji: str
+
+
+class ReactionResponse(BaseModel):
+    id: str
+    message_id: str
+    user_id: str
+    emoji: str
+
+
+# ─── Read State ───
+
+class ReadStateUpdate(BaseModel):
+    last_read_msg_id: str | None = None
+
+
+# ─── Mini-App Schemas ───
+
+class MiniAppResponse(BaseModel):
+    app_id: str
+    name: str
+    icon: str
+    description: str
+    plugin_name: str
+    render_schema: dict[str, Any] = Field(default_factory=dict)
+
+
+class MiniAppStartRequest(BaseModel):
+    app_id: str
+    config: dict[str, Any] = Field(default_factory=dict)
+
+
+# ─── WebSocket Message Schemas ───
+
+class WSMessage(BaseModel):
+    type: str
+    data: dict[str, Any] = Field(default_factory=dict)