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/@aws-sdk/credential-provider-web-identity/dist-cjs/fromWebToken.js

@@ -1,62 +0,0 @@
-"use strict";
-var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
-    if (k2 === undefined) k2 = k;
-    var desc = Object.getOwnPropertyDescriptor(m, k);
-    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
-      desc = { enumerable: true, get: function() { return m[k]; } };
-    }
-    Object.defineProperty(o, k2, desc);
-}) : (function(o, m, k, k2) {
-    if (k2 === undefined) k2 = k;
-    o[k2] = m[k];
-}));
-var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
-    Object.defineProperty(o, "default", { enumerable: true, value: v });
-}) : function(o, v) {
-    o["default"] = v;
-});
-var __importStar = (this && this.__importStar) || (function () {
-    var ownKeys = function(o) {
-        ownKeys = Object.getOwnPropertyNames || function (o) {
-            var ar = [];
-            for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
-            return ar;
-        };
-        return ownKeys(o);
-    };
-    return function (mod) {
-        if (mod && mod.__esModule) return mod;
-        var result = {};
-        if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
-        __setModuleDefault(result, mod);
-        return result;
-    };
-})();
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.fromWebToken = void 0;
-const fromWebToken = (init) => async (awsIdentityProperties) => {
-    init.logger?.debug("@aws-sdk/credential-provider-web-identity - fromWebToken");
-    const { roleArn, roleSessionName, webIdentityToken, providerId, policyArns, policy, durationSeconds } = init;
-    let { roleAssumerWithWebIdentity } = init;
-    if (!roleAssumerWithWebIdentity) {
-        const { getDefaultRoleAssumerWithWebIdentity } = await Promise.resolve().then(() => __importStar(require("@aws-sdk/nested-clients/sts")));
-        roleAssumerWithWebIdentity = getDefaultRoleAssumerWithWebIdentity({
-            ...init.clientConfig,
-            credentialProviderLogger: init.logger,
-            parentClientConfig: {
-                ...awsIdentityProperties?.callerClientConfig,
-                ...init.parentClientConfig,
-            },
-        }, init.clientPlugins);
-    }
-    return roleAssumerWithWebIdentity({
-        RoleArn: roleArn,
-        RoleSessionName: roleSessionName ?? `aws-sdk-js-session-${Date.now()}`,
-        WebIdentityToken: webIdentityToken,
-        ProviderId: providerId,
-        PolicyArns: policyArns,
-        Policy: policy,
-        DurationSeconds: durationSeconds,
-    });
-};
-exports.fromWebToken = fromWebToken;