feat: introduced nix packaging and path-based binary resolution

- Add comprehensive Nix flake definitions, derivations, modules, and CI workflows.
- Update tests and executables to resolve binaries from PATH rather than absolute paths.
- Ensure byte reproducibility and zeroed timestamps in embedded dashboard archives.
- Add handling for Nix-managed installations in CLI update checks.

packages/coding-agent/src/utils/external-editor.ts

@@ -5,7 +5,7 @@ import { spawn } from "node:child_process";
 import * as fs from "node:fs/promises";
 import * as os from "node:os";
 import * as path from "node:path";
-import { $env, Snowflake } from "@oh-my-pi/pi-utils";
+import { $env, $which, Snowflake } from "@oh-my-pi/pi-utils";
 
 /**
  * Returns the user's preferred editor command, or a platform default.
@@ -56,7 +56,7 @@ export async function openInEditor(
 		const child =
 			process.platform === "win32"
 				? spawn(editor, [...editorArgs, tmpFile], { stdio, shell: true })
-				: spawn("/bin/sh", ["-c", `${editorCmd} "$1"`, "sh", tmpFile], { stdio });
+				: spawn($which("sh") ?? "sh", ["-c", `${editorCmd} "$1"`, "sh", tmpFile], { stdio });
 		const { promise, reject, resolve } = Promise.withResolvers<number>();
 		child.once("exit", (code, signal) => resolve(code ?? (signal ? -1 : 0)));
 		child.once("error", error => reject(error));

packages/coding-agent/src/utils/git.ts

@@ -10,6 +10,7 @@ import {
 	parseNumstat,
 } from "../commit/git/diff";
 import type { FileDiff, FileHunks, NumstatEntry } from "../commit/types";
+import { REJECT_PROMPT_COMMAND } from "../exec/non-interactive-env";
 import { ToolAbortError, ToolError, throwIfAborted } from "../tools/tool-errors";
 
 // ════════════════════════════════════════════════════════════════════════════
@@ -199,7 +200,7 @@ const GIT_NON_INTERACTIVE_ENV = {
 	GIT_TERMINAL_PROMPT: "0",
 	LC_ALL: undefined,
 	LC_MESSAGES: "C",
-	SSH_ASKPASS: "/usr/bin/false",
+	SSH_ASKPASS: REJECT_PROMPT_COMMAND,
 } satisfies Record<string, string | undefined>;
 const GH_NON_INTERACTIVE_ENV = {
 	...GIT_NON_INTERACTIVE_ENV,