Reduce and tighten comments and docstrings across the test suite (#6429)

* Reduce and tighten comments and docstrings in tests

Shorten verbose comments and docstrings across the test suite without
changing any test logic. Remove narration that restates the next line,
collapse long module and test docstrings to a single line, and drop banner
separators. Keep regression context (issue and PR references, run ids),
skip reasons, mocking and timing rationale, license headers, lint and type
directives, and commented-out code.

Comments and docstrings only: an AST signature check confirms no code,
assertions, or string literals changed, and the suite byte-compiles cleanly.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests/studio/test_cli_run_alias.py

@@ -1,9 +1,4 @@
-"""Tests that ``unsloth run`` is registered as a top-level alias for
-``unsloth studio run``.
-
-AST-based to avoid importing ``unsloth_cli`` (which pulls in the heavy
-training stack) at test-collection time.
-"""
+"""AST-based tests that `unsloth run` is registered as a top-level alias for `unsloth studio run`."""
 
 from __future__ import annotations
 
@@ -35,8 +30,7 @@ def test_top_level_run_alias_registered():
             and call.func.value.id == "app"
         ):
             continue
-        # Decorator-call form has a string literal "run" as the first
-        # positional or as keyword ``name="run"``.
+        # "run" appears as the first positional arg or as keyword name="run".
         first_pos = call.args[0] if call.args else None
         keyword_name = next((kw.value for kw in call.keywords if kw.arg == "name"), None)
         is_run = (isinstance(first_pos, ast.Constant) and first_pos.value == "run") or (