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)

.env.example

@@ -0,0 +1,63 @@
+# =============================================================================
+# Konstruct — Environment Variables
+# Copy this file to .env and fill in the values.
+# NEVER commit .env to version control.
+# =============================================================================
+
+# -----------------------------------------------------------------------------
+# Database (PostgreSQL 16)
+# IMPORTANT: Use konstruct_app role, not the postgres superuser.
+# The postgres superuser bypasses RLS and must never be used by application code.
+# -----------------------------------------------------------------------------
+DATABASE_URL=postgresql+asyncpg://konstruct_app:konstruct_dev@localhost:5432/konstruct
+
+# For Alembic migrations (runs as postgres superuser to CREATE ROLE, enable RLS, etc.)
+DATABASE_ADMIN_URL=postgresql+asyncpg://postgres:postgres_dev@localhost:5432/konstruct
+
+# -----------------------------------------------------------------------------
+# Redis / Valkey
+# -----------------------------------------------------------------------------
+REDIS_URL=redis://localhost:6379/0
+
+# Celery broker and result backend
+CELERY_BROKER_URL=redis://localhost:6379/1
+CELERY_RESULT_BACKEND=redis://localhost:6379/2
+
+# -----------------------------------------------------------------------------
+# Slack
+# -----------------------------------------------------------------------------
+SLACK_BOT_TOKEN=xoxb-your-slack-bot-token
+SLACK_SIGNING_SECRET=your-slack-signing-secret
+SLACK_APP_TOKEN=xapp-your-slack-app-token  # For Socket Mode (optional)
+
+# -----------------------------------------------------------------------------
+# LLM Providers
+# -----------------------------------------------------------------------------
+ANTHROPIC_API_KEY=sk-ant-your-anthropic-api-key
+OPENAI_API_KEY=sk-your-openai-api-key
+OLLAMA_BASE_URL=http://localhost:11434
+
+# -----------------------------------------------------------------------------
+# Auth / Security
+# AUTH_SECRET: Used to sign JWT tokens for the admin portal.
+# Generate with: python -c "import secrets; print(secrets.token_hex(32))"
+# -----------------------------------------------------------------------------
+AUTH_SECRET=change-me-generate-with-secrets-token-hex-32
+
+# -----------------------------------------------------------------------------
+# Service URLs (internal)
+# -----------------------------------------------------------------------------
+GATEWAY_URL=http://localhost:8001
+ROUTER_URL=http://localhost:8002
+ORCHESTRATOR_URL=http://localhost:8003
+LLM_POOL_URL=http://localhost:8004
+
+# -----------------------------------------------------------------------------
+# Application Settings
+# -----------------------------------------------------------------------------
+ENVIRONMENT=development
+LOG_LEVEL=INFO
+DEBUG=false
+
+# Tenant rate limits (requests per minute defaults)
+DEFAULT_RATE_LIMIT_RPM=60