Give me an overview of this codebase. I'm trying to build a working mental model, not read every file. Cover: 1. **Architecture** — what kind of system is this, what are the main pieces, how do they talk to each other 2. **Key directories** — what lives where and why (top 5–10 only) 3. **Entry points** — where execution actually starts (server boot, CLI, background workers) 4. **Critical paths** — the 2–3 user-visible flows that touch the most code 5. **What's load-bearing** — files I should be careful about because half the codebase depends on them 6. **What's vestigial** — anything that looks abandoned, deprecated, or only kept for one weird customer Format as a structured doc. Use file paths, not vague descriptions. If something is unclear from the code, say so instead of inventing.
onboardingcodebasearchitecture