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/cache/persistence/TokenCacheContext.mjs

@@ -1,30 +0,0 @@
-/*! @azure/msal-common v15.13.1 2025-10-29 */
-'use strict';
-/*
- * Copyright (c) Microsoft Corporation. All rights reserved.
- * Licensed under the MIT License.
- */
-/**
- * This class instance helps track the memory changes facilitating
- * decisions to read from and write to the persistent cache
- */ class TokenCacheContext {
-    constructor(tokenCache, hasChanged) {
-        this.cache = tokenCache;
-        this.hasChanged = hasChanged;
-    }
-    /**
-     * boolean which indicates the changes in cache
-     */
-    get cacheHasChanged() {
-        return this.hasChanged;
-    }
-    /**
-     * function to retrieve the token cache
-     */
-    get tokenCache() {
-        return this.cache;
-    }
-}
-
-export { TokenCacheContext };
-//# sourceMappingURL=TokenCacheContext.mjs.map