[codex] Propagate plugin app categories (#27420)

## What
- Parse optional `.app.json` `category` overrides for plugin apps.
- Add nullable `category` to `AppSummary` and `AppTemplateSummary` in
the app-server protocol.
- Fall back from `branding.category` to the first non-empty
`app_metadata.categories` value when building app/template summaries.
- Regenerate schema/type fixtures and update plugin read/install tests.

## Why
The plugin details UI needs a normalized per-app category. Some apps
only provide their default category in metadata, while others need a
local `.app.json` override.

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -6416,6 +6416,12 @@
       "AppSummary": {
         "description": "EXPERIMENTAL - app metadata summary for plugin responses.",
         "properties": {
+          "category": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
           "description": {
             "type": [
               "string",
@@ -6449,6 +6455,12 @@
               "null"
             ]
           },
+          "category": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
           "description": {
             "type": [
               "string",

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -694,6 +694,12 @@
     "AppSummary": {
       "description": "EXPERIMENTAL - app metadata summary for plugin responses.",
       "properties": {
+        "category": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "description": {
           "type": [
             "string",
@@ -727,6 +733,12 @@
             "null"
           ]
         },
+        "category": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "description": {
           "type": [
             "string",

codex-rs/app-server-protocol/schema/json/v2/PluginInstallResponse.json

@@ -4,6 +4,12 @@
     "AppSummary": {
       "description": "EXPERIMENTAL - app metadata summary for plugin responses.",
       "properties": {
+        "category": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "description": {
           "type": [
             "string",

codex-rs/app-server-protocol/schema/json/v2/PluginReadResponse.json

@@ -8,6 +8,12 @@
     "AppSummary": {
       "description": "EXPERIMENTAL - app metadata summary for plugin responses.",
       "properties": {
+        "category": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "description": {
           "type": [
             "string",
@@ -41,6 +47,12 @@
             "null"
           ]
         },
+        "category": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
         "description": {
           "type": [
             "string",

codex-rs/app-server-protocol/schema/typescript/v2/AppSummary.ts

@@ -5,4 +5,4 @@
 /**
  * EXPERIMENTAL - app metadata summary for plugin responses.
  */
-export type AppSummary = { id: string, name: string, description: string | null, installUrl: string | null, };
+export type AppSummary = { id: string, name: string, description: string | null, installUrl: string | null, category: string | null, };

codex-rs/app-server-protocol/schema/typescript/v2/AppTemplateSummary.ts

@@ -3,4 +3,4 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AppTemplateUnavailableReason } from "./AppTemplateUnavailableReason";
 
-export type AppTemplateSummary = { templateId: string, name: string, description: string | null, canonicalConnectorId: string | null, logoUrl: string | null, logoUrlDark: string | null, materializedAppIds: Array<string>, reason: AppTemplateUnavailableReason | null, };
+export type AppTemplateSummary = { templateId: string, name: string, description: string | null, category: string | null, canonicalConnectorId: string | null, logoUrl: string | null, logoUrlDark: string | null, materializedAppIds: Array<string>, reason: AppTemplateUnavailableReason | null, };

codex-rs/app-server-protocol/src/protocol/v2/apps.rs

@@ -102,6 +102,33 @@ pub struct AppInfo {
     pub plugin_display_names: Vec<String>,
 }
 
+impl AppInfo {
+    pub fn category(&self) -> Option<String> {
+        self.branding
+            .as_ref()
+            .and_then(|branding| non_empty_category(branding.category.as_deref()))
+            .or_else(|| {
+                self.app_metadata
+                    .as_ref()
+                    .and_then(|metadata| metadata.categories.as_ref())
+                    .and_then(|categories| {
+                        categories
+                            .iter()
+                            .find_map(|category| non_empty_category(Some(category.as_str())))
+                    })
+            })
+    }
+}
+
+fn non_empty_category(category: Option<&str>) -> Option<String> {
+    let category = category?.trim();
+    if category.is_empty() {
+        None
+    } else {
+        Some(category.to_string())
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
@@ -111,15 +138,18 @@ pub struct AppSummary {
     pub name: String,
     pub description: Option<String>,
     pub install_url: Option<String>,
+    pub category: Option<String>,
 }
 
 impl From<AppInfo> for AppSummary {
     fn from(value: AppInfo) -> Self {
+        let category = value.category();
         Self {
             id: value.id,
             name: value.name,
             description: value.description,
             install_url: value.install_url,
+            category,
         }
     }
 }

codex-rs/app-server-protocol/src/protocol/v2/plugin.rs

@@ -661,6 +661,7 @@ pub struct AppTemplateSummary {
     pub template_id: String,
     pub name: String,
     pub description: Option<String>,
+    pub category: Option<String>,
     pub canonical_connector_id: Option<String>,
     pub logo_url: Option<String>,
     pub logo_url_dark: Option<String>,