chore(Mountain): deprecate direct Node fs proxy handlers

- Marks `native_fs.rs` handlers as deprecated with `ENOSYS` errors and warnings
- Replaces legacy FS proxying (Node 'fs' module) with `vscode.workspace.fs` API path
- Updates all handler functions to return standardized deprecation errors
- Adds logging to detect accidental usage of deprecated endpoints
- Retains file for historical reference while preventing active use

Aligns with Land's Path A strategy to enforce `workspace.fs` API usage through:
1. `handlers/workspace_fs_api.rs` for VS Code-compatible operations
2. Centralized Environment-managed FS via `River`/`Sun` Rust libraries
3. Improved security through controlled filesystem access patterns

This change ensures extensions follow supported FS interaction methods while
phasing out less secure direct Node module proxying in the Cocoon shim layer.

Author: NikolaRHristov

Source/handlers/native_fs.rs

@@ -0,0 +1,115 @@
+// ---------------------------------------------------------------------------------------------
+// Mountain Native FS Handlers (handlers/native_fs.rs) - DEPRECATED (Path A)
+// --------------------------------------------------------------------------------------------
+// This file previously handled low-level filesystem requests proxied directly
+// from Cocoon's Node 'fs' module shim (using `fs_*` method names).
+//
+// CURRENT STATUS (Path A with workspace.fs): **DEPRECATED/UNUSED**
+// With the implementation of the `vscode.workspace.fs` API shim
+// (`fs-api-shim.js`) and corresponding Mountain handlers
+// (`handlers/workspace_fs_api.rs`) which delegate to the Environment
+// implementation (`environment.rs`), direct proxying of the Node 'fs'
+// module implemented here is **not used** in the primary MVP Path A flow.
+//
+// Extensions *should* use `vscode.workspace.fs`. If direct Node 'fs' access
+// were re-enabled, these handlers would need significant updates, including
+// security checks and alignment with the Environment's FS capabilities.
+//
+// This file is kept for historical reference only and its functions should not
+// be called.
+// --------------------------------------------------------------------------------------------
+
+// ----- START: DEPRECATED Element/Mountain/src/handlers/native_fs.rs -----
+// NOTE: This entire file is DEPRECATED for Path A (vscode.workspace.fs)
+
+use std::path::PathBuf;
+
+// These imports might not be needed if the file is truly unused, but kept for context
+use Land_River::api as river_api;
+use Land_Sun::api as sun_api;
+// Use log crate if logging warnings about deprecation
+use log;
+use serde_json::{Value, json};
+use tauri::{AppHandle, Runtime, Window};
+
+const DEPRECATED_ERROR_MSG:&str = "Native FS handlers are deprecated; use workspace.fs API via effects/environment.";
+
+// --- Helper Functions (remain unchanged, but unused in Path A) ---
+fn create_error_string(message:String, code:Option<&str>) -> String {
+	json!({ "message": message, "code": code.unwrap_or("EUNKNOWN") }).to_string()
+}
+
+// Returns error immediately as path parsing is not relevant for deprecated
+// handlers
+fn path_from_uri_components(_params:&Value) -> Result<PathBuf, String> {
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+// --- Direct Action Handlers (remain deprecated stubs) ---
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_read_file<R:Runtime>(/* ... */) -> Result<Value, String> {
+	log::warn!("[FS Handler - DEPRECATED] Direct handle_read_file called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_write_file<R:Runtime>(/* ... */) -> Result<Value, String> {
+	log::warn!("[FS Handler - DEPRECATED] Direct handle_write_file called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+// --- Proxied Handlers (remain deprecated stubs) ---
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_stat(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_stat called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_realpath(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_realpath called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_read_file_proxy(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_read_file_proxy called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_write_file_proxy(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_write_file_proxy called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_mkdir_proxy(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_mkdir_proxy called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+/// **DEPRECATED:** Use `workspace.fs` API effects instead.
+pub async fn handle_fs_unlink_proxy(_params:Value) -> Result<Value, String> {
+	log::warn!("[FS Handler Proxy - DEPRECATED] handle_fs_unlink_proxy called.");
+
+	Err(create_error_string(DEPRECATED_ERROR_MSG.to_string(), Some("ENOSYS")))
+}
+
+// ... Add similar stubs for any other fs_* proxy handlers that existed ...
+// pub async fn handle_fs_readdir_proxy(...) -> Result<Value, String> { Err(...)
+// } pub async fn handle_fs_rename_proxy(...) -> Result<Value, String> {
+
+// Err(...) } pub async fn handle_fs_copy_proxy(...) -> Result<Value, String> {
+
+// Err(...) } pub async fn handle_fs_exists_proxy(...) -> Result<Value, String>
+// { Err(...) }
+
+// ----- END: DEPRECATED Element/Mountain/src/handlers/native_fs.rs -----