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/pages/docs/[...slug].astro

@@ -0,0 +1,19 @@
+---
+import { getCollection } from 'astro:content';
+import Docs from '../../layouts/Docs.astro';
+
+export async function getStaticPaths() {
+  const docs = await getCollection('docs');
+  return docs.map((entry) => ({
+    params: { slug: entry.slug },
+    props: { entry },
+  }));
+}
+
+const { entry } = Astro.props;
+const { Content } = await entry.render();
+---
+
+<Docs title={entry.data.title} description={entry.data.description} currentSlug={entry.slug}>
+  <Content />
+</Docs>