feat(auth,docs): add AGENTS guidelines, consistency kit, particle background, solid card, logo swap, header toggles, signup password rules, and phone input border fix

.editorconfig

@@ -0,0 +1,10 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+