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/@inquirer/confirm/dist/esm/index.mjs

@@ -1,33 +0,0 @@
-import { createPrompt, useState, useKeypress, isEnterKey, usePrefix, makeTheme, } from '@inquirer/core';
-export default createPrompt((config, done) => {
-    const { transformer = (answer) => (answer ? 'yes' : 'no') } = config;
-    const [status, setStatus] = useState('idle');
-    const [value, setValue] = useState('');
-    const theme = makeTheme(config.theme);
-    const prefix = usePrefix({ status, theme });
-    useKeypress((key, rl) => {
-        if (isEnterKey(key)) {
-            let answer = config.default !== false;
-            if (/^(y|yes)/i.test(value))
-                answer = true;
-            else if (/^(n|no)/i.test(value))
-                answer = false;
-            setValue(transformer(answer));
-            setStatus('done');
-            done(answer);
-        }
-        else {
-            setValue(rl.line);
-        }
-    });
-    let formattedValue = value;
-    let defaultValue = '';
-    if (status === 'done') {
-        formattedValue = theme.style.answer(value);
-    }
-    else {
-        defaultValue = ` ${theme.style.defaultAnswer(config.default === false ? 'y/N' : 'Y/n')}`;
-    }
-    const message = theme.style.message(config.message, status);
-    return `${prefix} ${message}${defaultValue} ${formattedValue}`;
-});