add .gitignore, clean up generated files from node_modules

Remove from tracking:
- dist/ (build output, regenerated by bun run build.ts)
- node_modules/.pnpm/ (pnpm internal store, 247MB)
- node_modules/.bin/ (executable symlinks)
- node_modules/.ignored/ and .ignored_* (source-map dirs moved aside by pnpm)
- 100 pnpm-installed package symlinks (regenerated by pnpm install)

Keep in tracking:
- Private package stubs not on npm (color-diff-napi, modifiers-napi,
  @ant/claude-for-chrome-mcp, @anthropic-ai/mcpb, @anthropic-ai/sandbox-runtime)
- Source-map extracted packages not installed by pnpm (@grpc/*, @protobufjs/*, etc.)

claude-code-source/node_modules/@azure/msal-common/dist/account/ClientInfo.mjs

@@ -1,46 +0,0 @@
-/*! @azure/msal-common v15.13.1 2025-10-29 */
-'use strict';
-import { createClientAuthError } from '../error/ClientAuthError.mjs';
-import { Separators, Constants } from '../utils/Constants.mjs';
-import { clientInfoEmptyError, clientInfoDecodingError } from '../error/ClientAuthErrorCodes.mjs';
-
-/*
- * Copyright (c) Microsoft Corporation. All rights reserved.
- * Licensed under the MIT License.
- */
-/**
- * Function to build a client info object from server clientInfo string
- * @param rawClientInfo
- * @param crypto
- */
-function buildClientInfo(rawClientInfo, base64Decode) {
-    if (!rawClientInfo) {
-        throw createClientAuthError(clientInfoEmptyError);
-    }
-    try {
-        const decodedClientInfo = base64Decode(rawClientInfo);
-        return JSON.parse(decodedClientInfo);
-    }
-    catch (e) {
-        throw createClientAuthError(clientInfoDecodingError);
-    }
-}
-/**
- * Function to build a client info object from cached homeAccountId string
- * @param homeAccountId
- */
-function buildClientInfoFromHomeAccountId(homeAccountId) {
-    if (!homeAccountId) {
-        throw createClientAuthError(clientInfoDecodingError);
-    }
-    const clientInfoParts = homeAccountId.split(Separators.CLIENT_INFO_SEPARATOR, 2);
-    return {
-        uid: clientInfoParts[0],
-        utid: clientInfoParts.length < 2
-            ? Constants.EMPTY_STRING
-            : clientInfoParts[1],
-    };
-}
-
-export { buildClientInfo, buildClientInfoFromHomeAccountId };
-//# sourceMappingURL=ClientInfo.mjs.map