Update stale 'four patterns' docstring in test (#123)

The pattern catalog grew from 4 to 7 entries during the
v0.11.0 cycle (state-migration-on-resume,
caller-supplied-trace-identifiers, observer-state-reconciliation
all landed). The test_get_returns_distinct_content_per_pattern
docstring + comment still referred to 'four patterns' /
'four slugs' / 'All four contents'. The assertion is
count-agnostic (uses patterns.list() length); only the prose
needs updating.

Surfaced by CoPilot review on main.

Author: chris-colinsky

tests/unit/test_patterns_api.py

@@ -72,12 +72,12 @@ def test_get_unknown_pattern_raises_key_error_with_known_names() -> None:
 
 
 def test_get_returns_distinct_content_per_pattern() -> None:
-    """Sanity check: the four patterns aren't accidentally aliasing
-    to the same payload (e.g., a generator bug that wrote one file's
-    content under all four slugs).
+    """Sanity check: the patterns aren't accidentally aliasing to
+    the same payload (e.g., a generator bug that wrote one file's
+    content under multiple slugs).
     """
     contents = {name: patterns.get(name) for name in patterns.list()}
-    # All four contents are unique.
+    # All contents are unique.
     assert len(set(contents.values())) == len(contents)