fix: prevent self-referential symlinks in sync_scripts_to_workspaces

When install.sh link_resources() creates workspace-*/scripts as a
directory-level symlink pointing to the project scripts/ dir, iterating
over it in sync_scripts_to_workspaces() produces dst_file paths that
resolve to the same real file as src_file.

The old idempotency check only skipped when dst_file itself was already a
symlink:

    if dst_file.is_symlink() and dst_file.resolve() == src_resolved:
        return False

For a workspace whose scripts/ directory is a symlink-to-directory,
dst_file appears as a regular file (is_symlink() == False), so the check
passes, the real source file is unlinked, and os.symlink() re-creates it
as a self-referential link (foo.py -> foo.py).  Running run_loop.sh every
15 s makes the whole scripts/ directory unusable within one cycle.

Fix: resolve dst_file before any other check and bail out early when
dst_resolved == src_resolved, regardless of whether dst_file itself is
stored as a symlink entry.

scripts/sync_agent_config.py

@@ -222,8 +222,19 @@ def _sync_script_symlink(src_file: pathlib.Path, dst_file: pathlib.Path) -> bool
     Returns True if the link was (re-)created, False if already up-to-date.
     """
     src_resolved = src_file.resolve()
+    # Guard: skip if dst resolves to the same real path as src.
+    # This happens when ws_scripts is itself a directory-level symlink pointing
+    # to the project scripts/ dir (created by install.sh link_resources).
+    # Without this check the function would unlink the real source file and
+    # then create a self-referential symlink (foo.py -> foo.py).
+    try:
+        dst_resolved = dst_file.resolve()
+    except OSError:
+        dst_resolved = None
+    if dst_resolved == src_resolved:
+        return False
     # Already a correct symlink?
-    if dst_file.is_symlink() and dst_file.resolve() == src_resolved:
+    if dst_file.is_symlink() and dst_resolved == src_resolved:
         return False
     # Remove stale file / old physical copy / broken symlink
     if dst_file.exists() or dst_file.is_symlink():