Add GPT-6-Astra to Amazon Bedrock catalogs (#42619)

## What changed

- Add `openai.gpt-6-astra` to the Amazon Bedrock model catalog.
- Include its global and US cross-region variants in the Bedrock Runtime catalog.
- Preserve the bundled model metadata while applying Bedrock-specific capabilities and identifiers.

## Testing

- Cover catalog ordering, metadata, context-window overrides, and runtime routing variants.
- Add TUI snapshots for the Bedrock model and reasoning pickers.

GitOrigin-RevId: 25895174f00b85a738da5bb94ade82feaacb474c

codex-rs/model-provider/src/provider.rs

@@ -1063,20 +1063,22 @@ mod tests {
             )
             .await;
         assert_eq!(uncached_catalog, catalog);
-        let model_info = manager
-            .get_model_info(
-                "openai.gpt-5.6-sol",
-                &ModelsManagerConfig {
-                    model_context_window: Some(1_000_000),
-                    ..Default::default()
-                },
-            )
-            .await;
-        let mut expected_model_info = manager
-            .get_model_info("openai.gpt-5.6-sol", &ModelsManagerConfig::default())
-            .await;
-        expected_model_info.context_window = Some(872_000);
-        assert_eq!(model_info, expected_model_info);
+        for slug in ["openai.gpt-5.6-sol", "openai.gpt-6-astra"] {
+            let model_info = manager
+                .get_model_info(
+                    slug,
+                    &ModelsManagerConfig {
+                        model_context_window: Some(1_000_000),
+                        ..Default::default()
+                    },
+                )
+                .await;
+            let mut expected_model_info = manager
+                .get_model_info(slug, &ModelsManagerConfig::default())
+                .await;
+            expected_model_info.context_window = Some(872_000);
+            assert_eq!(model_info, expected_model_info);
+        }
 
         let models = catalog
             .models
@@ -1088,6 +1090,7 @@ mod tests {
             models,
             vec![
                 ("openai.gpt-5.6-sol", "GPT-5.6 Sol"),
+                ("openai.gpt-6-astra", "GPT-6-Astra"),
                 ("openai.gpt-5.6-terra", "GPT-5.6 Terra"),
                 ("openai.gpt-5.6-luna", "GPT-5.6 Luna"),
                 ("openai.gpt-5.5", "GPT-5.5"),
@@ -1108,6 +1111,7 @@ mod tests {
                 .collect::<Vec<_>>(),
             vec![
                 "openai.gpt-5.6-sol",
+                "openai.gpt-6-astra",
                 "openai.gpt-5.6-terra",
                 "openai.gpt-5.6-luna",
                 "openai.gpt-5.5",