reconstruct and build @anthropic-ai/claude-code source from source map

- Extract 4756 source files from cli.js.map (57MB)
- Set up Bun build system with bun:bundle feature flag shim
- Configure 90+ compile-time feature flags matching production defaults
- Inject MACRO constants (VERSION, BUILD_TIME, etc.)
- Create stubs for private packages (color-diff-napi, modifiers-napi, etc.)
- Install all public dependencies via pnpm
- Patch commander v14 to allow multi-char short flags (-d2e)
- Build output: dist/cli.js (22MB), verified working

claude-code-source/node_modules/@smithy/.ignored_util-base64/dist-cjs/fromBase64.js

@@ -0,0 +1,16 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.fromBase64 = void 0;
+const util_buffer_from_1 = require("@smithy/util-buffer-from");
+const BASE64_REGEX = /^[A-Za-z0-9+/]*={0,2}$/;
+const fromBase64 = (input) => {
+    if ((input.length * 3) % 4 !== 0) {
+        throw new TypeError(`Incorrect padding on base64 string.`);
+    }
+    if (!BASE64_REGEX.exec(input)) {
+        throw new TypeError(`Invalid base64 string.`);
+    }
+    const buffer = (0, util_buffer_from_1.fromString)(input, "base64");
+    return new Uint8Array(buffer.buffer, buffer.byteOffset, buffer.byteLength);
+};
+exports.fromBase64 = fromBase64;