Display workspace usage limit error copy from response header (#24114)

## Why

`openai/openai#947613` adds `X-Codex-Rate-Limit-Reached-Type` for Codex
workspace credit-depletion and spend-cap responses. The CLI currently
reads the adjacent promo header but otherwise renders generic
usage-limit copy, so those responses do not explain the
workspace-specific action the user needs to take.

Backend dependency: https://github.com/openai/openai/pull/947613

## What Changed

- Parse `X-Codex-Rate-Limit-Reached-Type` in the usage-limit error
handling path alongside `x-codex-promo-message`.
- Keep the header value parsing with the shared `RateLimitReachedType`
enum.
- Carry the parsed type on `UsageLimitReachedError` and render
client-owned copy for the four workspace owner/member credit and
spend-cap values.
- Preserve existing promo and plan-based text for absent, generic, or
unknown header values.
- Keep the existing TUI workspace-owner nudge state path unchanged; the
response header only selects the displayed error string.
- Add focused display coverage for all specific type values and the
generic fallback case.

## Test Plan

- Added `usage_limit_reached_error_formats_rate_limit_reached_types`
coverage.
- Not run manually, per request; CI runs validation on the pushed
commit.

codex-rs/protocol/src/error.rs

@@ -7,6 +7,7 @@ use crate::exec_output::ExecToolCallOutput;
 use crate::network_policy::NetworkPolicyDecisionPayload;
 use crate::protocol::CodexErrorInfo;
 use crate::protocol::ErrorEvent;
+use crate::protocol::RateLimitReachedType;
 use crate::protocol::RateLimitSnapshot;
 use crate::protocol::TruncationPolicy;
 use chrono::DateTime;
@@ -451,6 +452,7 @@ pub struct UsageLimitReachedError {
     pub resets_at: Option<DateTime<Utc>>,
     pub rate_limits: Option<Box<RateLimitSnapshot>>,
     pub promo_message: Option<String>,
+    pub rate_limit_reached_type: Option<RateLimitReachedType>,
 }
 
 impl std::fmt::Display for UsageLimitReachedError {
@@ -470,6 +472,38 @@ impl std::fmt::Display for UsageLimitReachedError {
             );
         }
 
+        if let Some(rate_limit_reached_type) = self.rate_limit_reached_type {
+            match rate_limit_reached_type {
+                RateLimitReachedType::WorkspaceOwnerCreditsDepleted => {
+                    return write!(
+                        f,
+                        "Your workspace is out of credits. Add credits to continue."
+                    );
+                }
+                RateLimitReachedType::WorkspaceMemberCreditsDepleted => {
+                    return write!(
+                        f,
+                        "Your workspace is out of credits. Ask your workspace owner to refill in order to continue."
+                    );
+                }
+                RateLimitReachedType::WorkspaceOwnerUsageLimitReached => {
+                    return write!(
+                        f,
+                        "You hit your spend cap set in your workspace. Increase your spend cap to continue."
+                    );
+                }
+                RateLimitReachedType::WorkspaceMemberUsageLimitReached => {
+                    return write!(
+                        f,
+                        "You hit your spend cap set by the owner of your workspace. Ask an owner to increase your spend cap to continue."
+                    );
+                }
+                RateLimitReachedType::RateLimitReached => {
+                    // Generic limits intentionally use the existing promo or plan copy below.
+                }
+            }
+        }
+
         if let Some(promo_message) = &self.promo_message {
             return write!(
                 f,