feat(01-foundation-01): monorepo scaffolding, Docker Compose, and shared data models

- pyproject.toml: uv workspace with 5 member packages (shared, gateway, router, orchestrator, llm-pool)
- docker-compose.yml: PostgreSQL 16 + Redis 7 + Ollama services on konstruct-net
- .env.example: all required env vars documented, konstruct_app role (not superuser)
- scripts/init-db.sh: creates konstruct_app role at DB init time
- packages/shared/shared/config.py: Pydantic Settings loading all env vars
- packages/shared/shared/models/message.py: KonstructMessage, ChannelType, SenderInfo, MessageContent
- packages/shared/shared/models/tenant.py: Tenant, Agent, ChannelConnection SQLAlchemy 2.0 models
- packages/shared/shared/models/auth.py: PortalUser model for admin portal auth
- packages/shared/shared/db.py: async SQLAlchemy engine, session factory, get_session dependency
- packages/shared/shared/rls.py: current_tenant_id ContextVar and configure_rls_hook with parameterized SET LOCAL
- packages/shared/shared/redis_keys.py: tenant-namespaced key constructors (rate_limit, idempotency, session, engaged_thread)

packages/shared/shared/models/message.py

@@ -0,0 +1,93 @@
+"""
+KonstructMessage — the unified internal message format.
+
+All channel adapters (Slack, WhatsApp, Mattermost, etc.) normalize inbound
+events into this format before passing them to the Message Router. The core
+business logic never depends on which messaging platform a message came from.
+"""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from enum import StrEnum
+from typing import Any
+
+from pydantic import BaseModel, Field
+
+
+class ChannelType(StrEnum):
+    """Supported messaging channels."""
+
+    SLACK = "slack"
+    WHATSAPP = "whatsapp"
+    MATTERMOST = "mattermost"
+    ROCKETCHAT = "rocketchat"
+    TEAMS = "teams"
+    TELEGRAM = "telegram"
+    SIGNAL = "signal"
+
+
+class SenderInfo(BaseModel):
+    """Information about the message sender."""
+
+    user_id: str = Field(description="Channel-native user ID (e.g. Slack user ID U12345)")
+    display_name: str = Field(description="Human-readable display name")
+    email: str | None = Field(default=None, description="Sender email if available")
+    is_bot: bool = Field(default=False, description="True if sender is a bot/automation")
+
+
+class MessageContent(BaseModel):
+    """The content of a message — text and optional attachments."""
+
+    text: str = Field(description="Plain text content of the message")
+    html: str | None = Field(default=None, description="HTML-formatted content if available")
+    attachments: list[dict[str, Any]] = Field(
+        default_factory=list,
+        description="File attachments, images, or structured payloads",
+    )
+    mentions: list[str] = Field(
+        default_factory=list,
+        description="List of user/bot IDs mentioned in the message",
+    )
+
+
+class KonstructMessage(BaseModel):
+    """
+    Unified internal message format for Konstruct.
+
+    All channel adapters normalize events into this format. Downstream services
+    (Router, Orchestrator) operate exclusively on KonstructMessage — they never
+    inspect channel-specific fields directly.
+
+    `tenant_id` is None immediately after normalization. The Message Router
+    populates it via channel_connections lookup before forwarding.
+    """
+
+    id: str = Field(
+        default_factory=lambda: str(uuid.uuid4()),
+        description="Unique message ID (UUID)",
+    )
+    tenant_id: str | None = Field(
+        default=None,
+        description="Konstruct tenant ID — populated by Message Router after resolution",
+    )
+    channel: ChannelType = Field(description="Source messaging channel")
+    channel_metadata: dict[str, Any] = Field(
+        description="Channel-specific identifiers: workspace_id, channel_id, bot_user_id, etc."
+    )
+    sender: SenderInfo = Field(description="Message sender information")
+    content: MessageContent = Field(description="Message content")
+    timestamp: datetime = Field(description="Message timestamp (UTC)")
+    thread_id: str | None = Field(
+        default=None,
+        description="Thread identifier for threaded conversations (e.g. Slack thread_ts)",
+    )
+    reply_to: str | None = Field(
+        default=None,
+        description="Parent message ID if this is a reply",
+    )
+    context: dict[str, Any] = Field(
+        default_factory=dict,
+        description="Extracted intent, entities, sentiment — populated by downstream processors",
+    )