Major clean up and improvements to vimwiki compatibility and documentation.

Reviewed-on: #1

crates/nuwiki-core/src/date.rs

@@ -1,6 +1,6 @@
-//! Date primitives for the diary subsystem (Phase 16).
+//! Date primitives for the diary subsystem.
 //!
-//! v1.1 deliberately doesn't pull in `chrono` or `time`. The diary feature
+//! This crate deliberately doesn't pull in `chrono` or `time`. The diary feature
 //! only needs `YYYY-MM-DD` parsing/formatting and ±1 day arithmetic, which
 //! is small enough that the dependency cost outweighs the convenience.
 //!
@@ -56,7 +56,7 @@ impl DiaryDate {
         format!("{:04}-{:02}-{:02}", self.year, self.month, self.day)
     }
 
-    /// UTC "today" computed from `SystemTime::now()`. Phase 16's diary
+    /// UTC "today" computed from `SystemTime::now()`. The diary
     /// commands intentionally use UTC — local-time semantics depend on a
     /// timezone DB we don't ship and would surprise users crossing DST
     /// boundaries.