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/@smithy/middleware-endpoint/dist-cjs/adaptors/getEndpointFromConfig.js

@@ -1,7 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.getEndpointFromConfig = void 0;
-const node_config_provider_1 = require("@smithy/node-config-provider");
-const getEndpointUrlConfig_1 = require("./getEndpointUrlConfig");
-const getEndpointFromConfig = async (serviceId) => (0, node_config_provider_1.loadConfig)((0, getEndpointUrlConfig_1.getEndpointUrlConfig)(serviceId ?? ""))();
-exports.getEndpointFromConfig = getEndpointFromConfig;

claude-code-source/node_modules/@smithy/middleware-endpoint/dist-cjs/adaptors/getEndpointUrlConfig.js

@@ -1,35 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.getEndpointUrlConfig = void 0;
-const shared_ini_file_loader_1 = require("@smithy/shared-ini-file-loader");
-const ENV_ENDPOINT_URL = "AWS_ENDPOINT_URL";
-const CONFIG_ENDPOINT_URL = "endpoint_url";
-const getEndpointUrlConfig = (serviceId) => ({
-    environmentVariableSelector: (env) => {
-        const serviceSuffixParts = serviceId.split(" ").map((w) => w.toUpperCase());
-        const serviceEndpointUrl = env[[ENV_ENDPOINT_URL, ...serviceSuffixParts].join("_")];
-        if (serviceEndpointUrl)
-            return serviceEndpointUrl;
-        const endpointUrl = env[ENV_ENDPOINT_URL];
-        if (endpointUrl)
-            return endpointUrl;
-        return undefined;
-    },
-    configFileSelector: (profile, config) => {
-        if (config && profile.services) {
-            const servicesSection = config[["services", profile.services].join(shared_ini_file_loader_1.CONFIG_PREFIX_SEPARATOR)];
-            if (servicesSection) {
-                const servicePrefixParts = serviceId.split(" ").map((w) => w.toLowerCase());
-                const endpointUrl = servicesSection[[servicePrefixParts.join("_"), CONFIG_ENDPOINT_URL].join(shared_ini_file_loader_1.CONFIG_PREFIX_SEPARATOR)];
-                if (endpointUrl)
-                    return endpointUrl;
-            }
-        }
-        const endpointUrl = profile[CONFIG_ENDPOINT_URL];
-        if (endpointUrl)
-            return endpointUrl;
-        return undefined;
-    },
-    default: undefined,
-});
-exports.getEndpointUrlConfig = getEndpointUrlConfig;