aql: preserve inner \$ in string literals; fix notes tag regex for $ (fixes #5680)

packages/loot-core/src/server/aql/compiler.test.ts

@@ -161,6 +161,17 @@ describe('sheet language', () => {
     );
   });
 
+  it('does not strip inner regex dollar escapes in string literals', () => {
+    const result = generateSQLWithState(
+      q('transactions')
+        .filter({ 'payee.name': { $regexp: '\\$end' } })
+        .select(['id'])
+        .serialize(),
+      schemaWithRefs,
+    );
+    expect(result.sql).toMatch("REGEXP('\\\\$end', payees1.name)");
+  });
+
   it('`select` allows selecting all fields with *', () => {
     let result = generateSQLWithState(
       q('accounts').select(['*']).serialize(),

packages/loot-core/src/server/aql/compiler.ts

@@ -462,7 +462,10 @@ function compileLiteral(value) {
   } else if (typeof value === 'string') {
     // Allow user to escape $, and quote the string to make it a
     // string literal in the output
-    value = value.replace(/\\\$/g, '$');
+    // Only unescape a leading "\$" so users can write literals starting
+    // with "$" without triggering field reference parsing. Do not
+    // unescape inner "\$" occurrences to preserve regex escaping.
+    value = value.replace(/^\\\$/, '$');
     return typed(value, 'string', { literal: true });
   } else if (typeof value === 'boolean') {
     return typed(value ? 1 : 0, 'boolean', { literal: true });