Update System Knowledge Map

Perform a codebase archaeology investigation and update docs/SYSTEM_KNOWLEDGE_MAP.md with current system state.

Investigation Plan

Phase 1: Reconnaissance (Tech Stack)

1. Read package.json for dependencies and scripts
2. Read nuxt.config.ts for framework configuration
3. List app/ directory structure

Phase 2: Data Model Discovery (The Nouns)

1. Read content.config.ts for collection schemas and content types
2. Count items in content/, content/authors/, content/podcasts/
3. Identify any new entity types or schema changes

Phase 3: Capabilities Discovery (The Verbs)