Rename .pi to .feynman, rename citation agent to verifier, add website, skills, and docs

- Rename project config dir from .pi/ to .feynman/ (Pi supports this via piConfig.configDir)
- Rename citation agent to verifier across all prompts, agents, skills, and docs
- Add website with homepage and 24 doc pages (Astro + Tailwind)
- Add skills for all workflows (deep-research, lit, review, audit, replicate, compare, draft, autoresearch, watch, jobs, session-log, agentcomputer)
- Add Pi-native prompt frontmatter (args, section, topLevelCli) and read at runtime
- Remove sync-docs generation layer — docs are standalone
- Remove metadata/prompts.mjs and metadata/packages.mjs — not needed at runtime
- Rewrite README and homepage copy
- Add environment selection to /replicate before executing
- Add prompts/delegate.md and AGENTS.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

website/src/content/docs/getting-started/setup.md

@@ -0,0 +1,66 @@
+---
+title: Setup
+description: Detailed setup guide for Feynman
+section: Getting Started
+order: 3
+---
+
+## Guided setup
+
+```bash
+feynman setup
+```
+
+This walks through four steps:
+
+### Model provider authentication
+
+Feynman uses Pi's OAuth system for model access. The setup wizard prompts you to log in to your preferred provider.
+
+```bash
+feynman model login
+```
+
+### AlphaXiv login
+
+AlphaXiv powers Feynman's paper search and analysis tools. Sign in with:
+
+```bash
+feynman alpha login
+```
+
+Check status anytime:
+
+```bash
+feynman alpha status
+```
+
+### Web search routing
+
+Feynman supports three web search backends:
+
+- **auto** — Prefer Perplexity when configured, fall back to Gemini
+- **perplexity** — Force Perplexity Sonar
+- **gemini** — Force Gemini (default, zero-config via signed-in Chromium)
+
+The default path requires no API keys — it uses Gemini Browser via your signed-in Chromium profile.
+
+### Preview dependencies
+
+For PDF and HTML export of generated artifacts, Feynman needs `pandoc`:
+
+```bash
+feynman --setup-preview
+```
+
+This installs pandoc automatically on macOS/Homebrew systems.
+
+## Diagnostics
+
+Run the doctor to check everything:
+
+```bash
+feynman doctor
+```
+
+This verifies model auth, alphaXiv credentials, preview dependencies, and the Pi runtime.