docs: Update documentation for containerized IISA architecture #508

Overview

The IISA (Indexer Inference Serving Architecture) component has been migrated from an embedded Python service to a containerized HTTP service. This architectural change requires comprehensive documentation updates to reflect the new deployment model and HTTP client integration.

Background

Previously, IISA operated as an embedded Python component within the dipper service. The new architecture separates IISA into its own containerized service that communicates with dipper via HTTP. This separation improves maintainability, deployment flexibility, and service isolation.

Documentation Updates Required

The following documentation tasks need completion to reflect the containerized architecture:

Core Documentation

• 9.1 Update dipper-iisa README - Document the HTTP client implementation and remove all Python embedding references from dipper-iisa/README.md
• 9.2 Update dipper-service README - Document IISA configuration requirements and connection settings in bin/dipper-service/README.md

Architecture & Deployment

• 9.3 Architecture diagram - Create or update diagrams showing the dipper → IISA container relationship and communication flow
• 9.4 Deployment guide - Provide instructions for deploying the IISA container alongside dipper in production environments
• 9.5 Migration guide - Document the steps required to migrate from the embedded Python implementation to the HTTP-based containerized service

Code Documentation

• 9.6 Update code comments - Remove outdated Python references and update inline documentation across affected files

Acceptance Criteria

• All documentation accurately reflects the HTTP-based containerized architecture
• No references to the old embedded Python implementation remain
• Deployment and migration guides are clear and actionable
• Architecture diagrams show current system design
• Code comments align with the new implementation

Related Work

This issue tracks documentation updates for the IISA containerization work completed in recent commits (see git history on iisa-service branch).