Overhaul Feynman harness: streamline agents, prompts, and extensions

Remove legacy chains, skills, and config modules. Add citation agent,
SYSTEM.md, modular research-tools extension, and web-access layer.
Add ralph-wiggum to Pi package stack for long-running loops.

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

prompts/watch.md

@@ -4,11 +4,8 @@ description: Set up a recurring or deferred research watch on a topic, company,
 Create a research watch for: $@
 
 Requirements:
-- Start with a baseline sweep of the topic using the strongest relevant sources.
-- If the watch is about current events, products, markets, regulations, or releases, use `web_search` and `fetch_content` first.
-- If the watch has a literature component, add `alpha_search` and inspect the strongest papers directly.
+- Start with a baseline sweep of the topic.
 - Summarize what should be monitored, what signals matter, and what counts as a meaningful change.
 - Use `schedule_prompt` to create the recurring or delayed follow-up instead of merely promising to check later.
-- If the user wants detached execution for the initial sweep, use `subagent` in background mode and report how to inspect status.
-- Save exactly one durable baseline artifact to `outputs/`.
+- Save exactly one baseline artifact to `outputs/`.
 - End with a `Sources` section containing direct URLs for every source used.