fix: auto-detect date format (DD/MM vs MM/DD) in CSV imports

Scans all date values in imported CSVs to determine whether the file
uses DD/MM/YYYY or MM/DD/YYYY format. When the format is ambiguous
(all day and month values are <= 12), shows an inline dropdown for the
user to choose. Bump version to 1.0.2.

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "zeroclock"
-version = "1.0.1"
+version = "1.0.2"
 description = "A local time tracking app with invoicing"
 authors = ["you"]
 edition = "2021"