shimmer on working (#1807)

change the animation on "working" to be a text shimmer


https://github.com/user-attachments/assets/f64529eb-1c64-493a-8d97-0f68b964bdd0

codex-rs/Cargo.lock

@@ -869,6 +869,7 @@ dependencies = [
  "shlex",
  "strum 0.27.2",
  "strum_macros 0.27.2",
+ "supports-color",
  "textwrap 0.16.2",
  "tokio",
  "tracing",
@@ -2337,6 +2338,12 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "is_ci"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7655c9839580ee829dfacba1d1278c2b7883e50a277ff7541299489d6bdfdc45"
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.1"
@@ -4378,6 +4385,15 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
+[[package]]
+name = "supports-color"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c64fc7232dd8d2e4ac5ce4ef302b1d81e0b80d055b9d77c7c4f51f6aa4c867d6"
+dependencies = [
+ "is_ci",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.109"