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/middleware-logger/dist-cjs/index.js

@@ -1,48 +0,0 @@
-'use strict';
-
-const loggerMiddleware = () => (next, context) => async (args) => {
-    try {
-        const response = await next(args);
-        const { clientName, commandName, logger, dynamoDbDocumentClientOptions = {} } = context;
-        const { overrideInputFilterSensitiveLog, overrideOutputFilterSensitiveLog } = dynamoDbDocumentClientOptions;
-        const inputFilterSensitiveLog = overrideInputFilterSensitiveLog ?? context.inputFilterSensitiveLog;
-        const outputFilterSensitiveLog = overrideOutputFilterSensitiveLog ?? context.outputFilterSensitiveLog;
-        const { $metadata, ...outputWithoutMetadata } = response.output;
-        logger?.info?.({
-            clientName,
-            commandName,
-            input: inputFilterSensitiveLog(args.input),
-            output: outputFilterSensitiveLog(outputWithoutMetadata),
-            metadata: $metadata,
-        });
-        return response;
-    }
-    catch (error) {
-        const { clientName, commandName, logger, dynamoDbDocumentClientOptions = {} } = context;
-        const { overrideInputFilterSensitiveLog } = dynamoDbDocumentClientOptions;
-        const inputFilterSensitiveLog = overrideInputFilterSensitiveLog ?? context.inputFilterSensitiveLog;
-        logger?.error?.({
-            clientName,
-            commandName,
-            input: inputFilterSensitiveLog(args.input),
-            error,
-            metadata: error.$metadata,
-        });
-        throw error;
-    }
-};
-const loggerMiddlewareOptions = {
-    name: "loggerMiddleware",
-    tags: ["LOGGER"],
-    step: "initialize",
-    override: true,
-};
-const getLoggerPlugin = (options) => ({
-    applyToStack: (clientStack) => {
-        clientStack.add(loggerMiddleware(), loggerMiddlewareOptions);
-    },
-});
-
-exports.getLoggerPlugin = getLoggerPlugin;
-exports.loggerMiddleware = loggerMiddleware;
-exports.loggerMiddlewareOptions = loggerMiddlewareOptions;