Shorten the statement statuses

The statements list now reads imported, changed, not imported and gone
from disk. What each means is in the README's statements table.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/web/static/app.js

@@ -290,9 +290,9 @@ function mountAccounts(main) {
 
 const FILE_STATUS = {
   imported: ['✓', '', 'imported'],
-  changed: ['⚠', 'warn', 'changed since it was imported — Import re-reads it'],
-  new: ['•', 'warn', 'not imported — press Import (a file that fails to parse stays here)'],
-  missing: ['✗', 'neg', 'gone from disk — its rows stay only until the index is rebuilt'],
+  changed: ['⚠', 'warn', 'changed'],
+  new: ['•', 'warn', 'not imported'],
+  missing: ['✗', 'neg', 'gone from disk'],
 };
 
 // fileList shows the statements in every account folder beside what the index