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>

extensions/research-tools/project.ts

@@ -0,0 +1,115 @@
+import { mkdir, stat, writeFile } from "node:fs/promises";
+import { dirname, resolve as resolvePath } from "node:path";
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+import { Type } from "@sinclair/typebox";
+
+import { renderHtmlPreview, renderPdfPreview, openWithDefaultApp, pathExists, buildProjectAgentsTemplate, buildSessionLogsReadme } from "./preview.js";
+import { formatToolText } from "./shared.js";
+import { searchSessionTranscripts } from "./session-search.js";
+
+export function registerInitCommand(pi: ExtensionAPI): void {
+	pi.registerCommand("init", {
+		description: "Initialize AGENTS.md and session-log folders for a research project.",
+		handler: async (_args, ctx) => {
+			const agentsPath = resolvePath(ctx.cwd, "AGENTS.md");
+			const notesDir = resolvePath(ctx.cwd, "notes");
+			const sessionLogsDir = resolvePath(notesDir, "session-logs");
+			const sessionLogsReadmePath = resolvePath(sessionLogsDir, "README.md");
+			const created: string[] = [];
+			const skipped: string[] = [];
+
+			await mkdir(notesDir, { recursive: true });
+			await mkdir(sessionLogsDir, { recursive: true });
+
+			if (!(await pathExists(agentsPath))) {
+				await writeFile(agentsPath, buildProjectAgentsTemplate(), "utf8");
+				created.push("AGENTS.md");
+			} else {
+				skipped.push("AGENTS.md");
+			}
+
+			if (!(await pathExists(sessionLogsReadmePath))) {
+				await writeFile(sessionLogsReadmePath, buildSessionLogsReadme(), "utf8");
+				created.push("notes/session-logs/README.md");
+			} else {
+				skipped.push("notes/session-logs/README.md");
+			}
+
+			const createdSummary = created.length > 0 ? `created: ${created.join(", ")}` : "created: nothing";
+			const skippedSummary = skipped.length > 0 ? `; kept existing: ${skipped.join(", ")}` : "";
+			ctx.ui.notify(`${createdSummary}${skippedSummary}`, "info");
+		},
+	});
+}
+
+export function registerSessionSearchTool(pi: ExtensionAPI): void {
+	pi.registerTool({
+		name: "session_search",
+		label: "Session Search",
+		description: "Search prior Feynman session transcripts to recover what was done, said, or written before.",
+		parameters: Type.Object({
+			query: Type.String({
+				description: "Search query to look for in past sessions.",
+			}),
+			limit: Type.Optional(
+				Type.Number({
+					description: "Maximum number of sessions to return. Defaults to 3.",
+				}),
+			),
+		}),
+		async execute(_toolCallId, params) {
+			const result = await searchSessionTranscripts(params.query, Math.max(1, Math.min(params.limit ?? 3, 8)));
+			return {
+				content: [{ type: "text", text: formatToolText(result) }],
+				details: result,
+			};
+		},
+	});
+}
+
+export function registerPreviewTool(pi: ExtensionAPI): void {
+	pi.registerTool({
+		name: "preview_file",
+		label: "Preview File",
+		description: "Open a markdown, LaTeX, PDF, or code artifact in the browser or a PDF viewer for human review. Rendered HTML/PDF previews are temporary and do not replace the source artifact.",
+		parameters: Type.Object({
+			path: Type.String({
+				description: "Path to the file to preview.",
+			}),
+			target: Type.Optional(
+				Type.String({
+					description: "Preview target: browser or pdf. Defaults to browser.",
+				}),
+			),
+		}),
+		async execute(_toolCallId, params, _signal, _onUpdate, ctx) {
+			const target = (params.target?.trim().toLowerCase() || "browser");
+			if (target !== "browser" && target !== "pdf") {
+				throw new Error("target must be browser or pdf");
+			}
+
+			const resolvedPath = resolvePath(ctx.cwd, params.path);
+			const openedPath =
+				resolvePath(resolvedPath).toLowerCase().endsWith(".pdf") && target === "pdf"
+					? resolvedPath
+					: target === "pdf"
+						? await renderPdfPreview(resolvedPath)
+						: await renderHtmlPreview(resolvedPath);
+
+			await mkdir(dirname(openedPath), { recursive: true }).catch(() => {});
+			await openWithDefaultApp(openedPath);
+
+			const result = {
+				sourcePath: resolvedPath,
+				target,
+				openedPath,
+				temporaryPreview: openedPath !== resolvedPath,
+			};
+			return {
+				content: [{ type: "text", text: formatToolText(result) }],
+				details: result,
+			};
+		},
+	});
+}