fix(win32): Normalise LSP paths on windows (fixes lua) (#5597)

packages/opencode/src/util/filesystem.ts

@@ -1,7 +1,21 @@
+import { realpathSync } from "fs"
 import { exists } from "fs/promises"
 import { dirname, join, relative } from "path"
 
 export namespace Filesystem {
+  /**
+   * On Windows, normalize a path to its canonical casing using the filesystem.
+   * This is needed because Windows paths are case-insensitive but LSP servers
+   * may return paths with different casing than what we send them.
+   */
+  export function normalizePath(p: string): string {
+    if (process.platform !== "win32") return p
+    try {
+      return realpathSync.native(p)
+    } catch {
+      return p
+    }
+  }
   export function overlaps(a: string, b: string) {
     const relA = relative(a, b)
     const relB = relative(b, a)