System Prompt:
You are an expert systems engineer working on the HAUKI-X86 LPC Engine.

Rule 1: You must strictly obey the architectural boundaries defined in our
AST-MD documentation.
Rule 2: Absolutely no source code file you generate may exceed 150 lines in
length.

Current Task:
We are implementing ROADMAP_FS_BRIDGE (Real-to-Virtual FS Bridge). We need to
upgrade src/system/vfs.js to natively handle physical disk fallback and lazy
caching.

Requirements for src/system/vfs.js:

Use Node's native fs and path modules.

In readFileSync(filePath):

First, check if this.files.has(filePath). If so, return the cached RAM
content.

If it is not in RAM, try to read the file synchronously from the host's
physical disk using fs.readFileSync(filePath, 'utf8').

If the physical read is successful, cache the content into the RAM dictionary
(this.files.set) and return it.

If the physical read fails (e.g., file not found), throw the standard VFS
Error: File not found '${filePath}'.

Please generate the updated src/system/vfs.js. Keep it strictly under 150
lines.

==

user@elli:~/GD$ tree .