Support self-serve Business ProLite accounts (#35785)

## What changed

- Recognize `self_serve_business_prolite` across authentication, account and rate-limit APIs, generated schemas, workspace classification, status display, cloud configuration gating, and usage-limit messaging.
- Keep the Python SDK's `PlanType` enum compatible with non-empty string values introduced by newer Codex runtimes while preserving its known constants.

## Testing

- Cover token parsing, account reads and notifications, backend rate-limit mapping, workspace behavior, error formatting, and Python SDK response coercion for the new plan value.

GitOrigin-RevId: 70bc17a7c4ba4028cb10e4333cc1f2ac64da361f

codex-rs/protocol/src/auth.rs

@@ -71,6 +71,7 @@ impl PlanType {
             "pro" => Self::Known(KnownPlan::Pro),
             "prolite" => Self::Known(KnownPlan::ProLite),
             "team" => Self::Known(KnownPlan::Team),
+            "self_serve_business_prolite" => Self::Known(KnownPlan::SelfServeBusinessProLite),
             "self_serve_business_usage_based" => {
                 Self::Known(KnownPlan::SelfServeBusinessUsageBased)
             }
@@ -93,6 +94,8 @@ pub enum KnownPlan {
     Pro,
     ProLite,
     Team,
+    #[serde(rename = "self_serve_business_prolite")]
+    SelfServeBusinessProLite,
     #[serde(rename = "self_serve_business_usage_based")]
     SelfServeBusinessUsageBased,
     Business,
@@ -114,6 +117,7 @@ impl KnownPlan {
             Self::Pro => "Pro",
             Self::ProLite => "Pro Lite",
             Self::Team => "Team",
+            Self::SelfServeBusinessProLite => "Self Serve Business ProLite",
             Self::SelfServeBusinessUsageBased => "Self Serve Business Usage Based",
             Self::Business => "Business",
             Self::Ent26 => "Enterprise",
@@ -131,6 +135,7 @@ impl KnownPlan {
             Self::Pro => "pro",
             Self::ProLite => "prolite",
             Self::Team => "team",
+            Self::SelfServeBusinessProLite => "self_serve_business_prolite",
             Self::SelfServeBusinessUsageBased => "self_serve_business_usage_based",
             Self::Business => "business",
             Self::Ent26 => "ent26",
@@ -144,6 +149,7 @@ impl KnownPlan {
         matches!(
             self,
             Self::Team
+                | Self::SelfServeBusinessProLite
                 | Self::SelfServeBusinessUsageBased
                 | Self::Business
                 | Self::Ent26