Clarify what the fresh-resolution test guards

With uv.lock committed, bare uv run consumes the lock and never
resolves fresh. The fresh resolve happens on lock regeneration (uv
lock after any pyproject.toml change) and on uv run's silent re-lock
of a stale lockfile; say that instead of the bare-machine claim.

Author: myurasov-nv

source/isaaclab/test/install_ci/misc/test_uv_fresh_resolution_smoke.py

@@ -8,8 +8,8 @@
     - (none: the test resolves dependencies only and does not install anything)
 Tests:
     - uv lock --upgrade --dry-run -> verify the full dependency graph (all extras, all
-      platforms) re-resolves from the live public indexes, i.e. ``uv run`` works from
-      a bare machine
+      platforms) re-resolves from the live public indexes, so the lockfile can be
+      regenerated after any pyproject.toml change
 """
 
 from __future__ import annotations
@@ -26,11 +26,13 @@ class Test_Uv_Fresh_Resolution_Smoke:
     """A fresh, full-graph resolution must succeed from the public indexes.
 
     ``uv lock --upgrade --dry-run`` re-resolves every dependency, extra, and platform
-    fork from scratch without writing the lockfile or installing anything - exactly
-    what ``uv run`` does on a bare machine before the first lock exists. This is the
-    check that catches a pin that only resolves against internal infrastructure
-    (e.g. an unpublished ``ovphysx==0.5.2+head...`` build) or a marker split uv
-    cannot satisfy.
+    fork from scratch, ignoring the committed lockfile and without writing or
+    installing anything. The committed lock shields ``uv run`` users from resolution,
+    but a fresh resolve still happens whenever the lock must be regenerated: any
+    contributor changing ``pyproject.toml`` runs ``uv lock``, and ``uv run`` silently
+    re-resolves when the lock is stale. This is the check that catches a pin that
+    only resolves against internal infrastructure (e.g. an unpublished
+    ``ovphysx==0.5.2+head...`` build) or a marker split uv cannot satisfy.
 
     Complements the neighbouring checks: ``test_uv_lock_check_smoke`` validates the
     committed lock is current, the ``uv_run/`` tests validate the committed lock
@@ -48,7 +50,8 @@ def test_uv_lock_upgrade_resolves_all_extras_from_public_indexes(self, isaaclab_
         """Verify ``uv lock --upgrade --dry-run`` resolves the full graph fresh."""
         result = run_cmd(["uv", "lock", "--upgrade", "--dry-run"], cwd=isaaclab_root, timeout=880)
         assert result.returncode == 0, (
-            "Fresh full-graph resolution failed, so `uv run` is broken on a bare machine."
-            " A dependency (often in an optional extra) no longer resolves from the public"
-            f" indexes, or a marker split is unsatisfiable:\n{result.stdout}\n{result.stderr}"
+            "Fresh full-graph resolution failed: the lockfile can no longer be regenerated"
+            " (`uv lock` after a pyproject.toml change will fail, and `uv run` will fail on"
+            " a stale lock). A dependency, often in an optional extra, no longer resolves"
+            f" from the public indexes, or a marker split is unsatisfiable:\n{result.stdout}\n{result.stderr}"
         )