fix(plugins): keep pinned program paths out of the verbatim form (#2012)

std::fs::canonicalize returns \\?\-prefixed paths on Windows, so a process grant's pinned program path was stored in that form. Canonicalize the program's directory with dunce, which keeps the usual form.

Fixes #2001

Co-authored-by: zaojiaoci <31303376+zaojiaoci@users.noreply.github.com>

crates/ide-extension/Cargo.toml

@@ -18,6 +18,7 @@ semver = "1"
 blake3.workspace = true
 zip.workspace = true
 base64.workspace = true
+dunce.workspace = true
 ed25519-dalek = "3"
 
 [dev-dependencies]

crates/ide-extension/src/ledger.rs

@@ -441,11 +441,13 @@ pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf,
 /// `p` with its parent canonicalized but the file name as found: PATH
 /// entries like `/var` → `/private/var` (macOS) or `~` links collapse to
 /// their real directory, while a linked program (`cargo` → rustup) keeps
-/// its link name so the shim still dispatches on argv[0].
+/// its link name so the shim still dispatches on argv[0]. `dunce` keeps the
+/// path in its usual form on Windows: a `\\?\`-prefixed pin would never
+/// match the path the program was actually started with.
 fn canonical_dir(p: &Path) -> PathBuf {
     let Some(dir) = p.parent() else { return p.to_path_buf() };
     let Some(name) = p.file_name() else { return p.to_path_buf() };
-    std::fs::canonicalize(dir).map(|d| d.join(name)).unwrap_or_else(|_| p.to_path_buf())
+    dunce::canonicalize(dir).map(|d| d.join(name)).unwrap_or_else(|_| p.to_path_buf())
 }
 
 fn is_executable(p: &Path) -> bool {
@@ -498,6 +500,20 @@ mod tests {
         list.iter().map(|s| s.parse().unwrap()).collect()
     }
 
+    #[test]
+    #[cfg(windows)]
+    fn pinned_program_path_has_no_verbatim_prefix() {
+        // std::fs::canonicalize returns \\?\-prefixed paths on Windows; a pin
+        // stored in that form would never match the plain path the program is
+        // started with. dunce keeps the usual form.
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("cargo.exe"), b"").unwrap();
+        let pinned = resolve_program("cargo.exe", Some(dir.path().as_os_str())).unwrap();
+        let shown = pinned.to_string_lossy();
+        assert!(!shown.starts_with(r"\\?\"), "verbatim prefix leaked into the pin: {shown}");
+        assert!(pinned.is_absolute());
+    }
+
     fn req<'a>(version: &'a str, hash: &'a str, required: &[&str], optional: &[&str]) -> Request<'a> {
         Request {
             subject: Subject::Installed("p".into()),