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/util-defaults-mode-node/dist-cjs/index.js

@@ -1,74 +0,0 @@
-'use strict';
-
-var configResolver = require('@smithy/config-resolver');
-var nodeConfigProvider = require('@smithy/node-config-provider');
-var propertyProvider = require('@smithy/property-provider');
-
-const AWS_EXECUTION_ENV = "AWS_EXECUTION_ENV";
-const AWS_REGION_ENV = "AWS_REGION";
-const AWS_DEFAULT_REGION_ENV = "AWS_DEFAULT_REGION";
-const ENV_IMDS_DISABLED = "AWS_EC2_METADATA_DISABLED";
-const DEFAULTS_MODE_OPTIONS = ["in-region", "cross-region", "mobile", "standard", "legacy"];
-const IMDS_REGION_PATH = "/latest/meta-data/placement/region";
-
-const AWS_DEFAULTS_MODE_ENV = "AWS_DEFAULTS_MODE";
-const AWS_DEFAULTS_MODE_CONFIG = "defaults_mode";
-const NODE_DEFAULTS_MODE_CONFIG_OPTIONS = {
-    environmentVariableSelector: (env) => {
-        return env[AWS_DEFAULTS_MODE_ENV];
-    },
-    configFileSelector: (profile) => {
-        return profile[AWS_DEFAULTS_MODE_CONFIG];
-    },
-    default: "legacy",
-};
-
-const resolveDefaultsModeConfig = ({ region = nodeConfigProvider.loadConfig(configResolver.NODE_REGION_CONFIG_OPTIONS), defaultsMode = nodeConfigProvider.loadConfig(NODE_DEFAULTS_MODE_CONFIG_OPTIONS), } = {}) => propertyProvider.memoize(async () => {
-    const mode = typeof defaultsMode === "function" ? await defaultsMode() : defaultsMode;
-    switch (mode?.toLowerCase()) {
-        case "auto":
-            return resolveNodeDefaultsModeAuto(region);
-        case "in-region":
-        case "cross-region":
-        case "mobile":
-        case "standard":
-        case "legacy":
-            return Promise.resolve(mode?.toLocaleLowerCase());
-        case undefined:
-            return Promise.resolve("legacy");
-        default:
-            throw new Error(`Invalid parameter for "defaultsMode", expect ${DEFAULTS_MODE_OPTIONS.join(", ")}, got ${mode}`);
-    }
-});
-const resolveNodeDefaultsModeAuto = async (clientRegion) => {
-    if (clientRegion) {
-        const resolvedRegion = typeof clientRegion === "function" ? await clientRegion() : clientRegion;
-        const inferredRegion = await inferPhysicalRegion();
-        if (!inferredRegion) {
-            return "standard";
-        }
-        if (resolvedRegion === inferredRegion) {
-            return "in-region";
-        }
-        else {
-            return "cross-region";
-        }
-    }
-    return "standard";
-};
-const inferPhysicalRegion = async () => {
-    if (process.env[AWS_EXECUTION_ENV] && (process.env[AWS_REGION_ENV] || process.env[AWS_DEFAULT_REGION_ENV])) {
-        return process.env[AWS_REGION_ENV] ?? process.env[AWS_DEFAULT_REGION_ENV];
-    }
-    if (!process.env[ENV_IMDS_DISABLED]) {
-        try {
-            const { getInstanceMetadataEndpoint, httpRequest } = await import('@smithy/credential-provider-imds');
-            const endpoint = await getInstanceMetadataEndpoint();
-            return (await httpRequest({ ...endpoint, path: IMDS_REGION_PATH })).toString();
-        }
-        catch (e) {
-        }
-    }
-};
-
-exports.resolveDefaultsModeConfig = resolveDefaultsModeConfig;