fix: Drop dotenv package and use native process.loadEnvFile (#152)

* Initial plan

* Replace dotenv with native process.loadEnvFile

Co-authored-by: nzakas <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: nzakas <[email protected]>

Author: Copilot

README.md

@@ -295,7 +295,7 @@ Claude will then create a `claude_desktop_config.json` file. Open it and add the
 
 This example enables Mastodon and LinkedIn so the `env` key contains the environment variables necessary to post to those services. You can customize the services by passing different command line arguments as you would using the CLI.
 
-If you'd prefer not to put your environment variables directly into the JSON file, you can create a [`.env` file](https://www.npmjs.com/package/dotenv) and use the `CROSSPOST_DOTENV` environment variable to point to it:
+If you'd prefer not to put your environment variables directly into the JSON file, you can create a `.env` file and use the `CROSSPOST_DOTENV` environment variable to point to it:
 
 ```json
 {

package-lock.json

@@ -97,7 +97,6 @@
     "@modelcontextprotocol/sdk": "^1.8.0",
     "@noble/secp256k1": "^3.0.0",
     "bech32": "^2.0.0",
-    "dotenv": "^16.6.1",
     "tlds": "^1.255.0",
     "twitter-api-v2": "^1.20.2",
     "zod": "^3.24.2"

package.json

@@ -10,7 +10,6 @@
 
 import fs from "node:fs";
 import { parseArgs } from "node:util";
-import * as dotenv from "dotenv";
 import { Env } from "@humanwhocodes/env";
 import {
 	Client,
@@ -134,10 +133,16 @@ if (
 // load environment variables from .env file if present
 if (process.env.CROSSPOST_DOTENV) {
 	const filePath =
-		process.env.CROSSPOST_DOTENV === "1"
-			? undefined
-			: process.env.CROSSPOST_DOTENV;
-	dotenv.config({ path: filePath });
+		process.env.CROSSPOST_DOTENV === "1" ? ".env" : process.env.CROSSPOST_DOTENV;
+	try {
+		process.loadEnvFile(filePath);
+	} catch (err) {
+		// Ignore if file doesn't exist, similar to dotenv behavior
+		const error = /** @type {NodeJS.ErrnoException} */ (err);
+		if (error.code !== "ENOENT") {
+			throw error;
+		}
+	}
 }
 
 const env = new Env();