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/tools/session-search.md

@@ -0,0 +1,26 @@
+---
+title: Session Search
+description: Search prior Feynman session transcripts
+section: Tools
+order: 3
+---
+
+## Overview
+
+The `session_search` tool recovers prior Feynman work from stored session transcripts. Useful for picking up previous research threads or finding past findings.
+
+## Usage
+
+Inside the REPL:
+
+```
+/search
+```
+
+Or use the tool directly — Feynman will invoke `session_search` automatically when you reference prior work.
+
+## What it searches
+
+- Full session transcripts
+- Tool outputs and agent results
+- Generated artifacts and their content