tla(composed): missed _proposed_ -> _partial_ ref (claude[bot] on PR #927)

claude[bot] review of b527dd5 flagged tla/composed/Composed.tla:93
as a missed reference.  My earlier rg sweep was scoped to
--include=*.go/*.clj/*.sh/*.md and did not match .tla files.

$ grep -rn '2026_(05_29|06_02)_proposed_composed1' . -> 0 hits
after this fix.

Author: bootjp

tla/composed/Composed.tla

@@ -90,7 +90,7 @@ VARIABLES
                             \* observed-version check and the apply-time
                             \* current-version cross-version-read fence
                             \* (Composed-1a; see docs/design/
-                            \* 2026_05_29_proposed_composed1_cross_group_commit_guard.md
+                            \* 2026_05_29_partial_composed1_cross_group_commit_guard.md
                             \* §4.4 and §5).
     opCount