feat(settings): add model provider management with full CRUD support

Add a new settings page for managing API model providers (name, API URL,
API key, applicable agent types). Includes database migration, SeaORM
entity, backend CRUD commands/handlers, frontend settings UI with agent
type filter, add/edit/delete dialogs, and i18n support for all 10 locales.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/src/web/handlers/mod.rs

@@ -7,6 +7,7 @@ pub mod folder_commands;
 pub mod folders;
 pub mod git;
 pub mod mcp;
+pub mod model_provider;
 pub mod project_boot;
 pub mod system_settings;
 pub mod terminal;

src-tauri/src/web/handlers/model_provider.rs

@@ -0,0 +1,88 @@
+use std::sync::Arc;
+
+use axum::{extract::Extension, Json};
+use serde::Deserialize;
+
+use crate::app_error::AppCommandError;
+use crate::app_state::AppState;
+use crate::commands::model_provider as mp_commands;
+use crate::models::model_provider::ModelProviderInfo;
+
+// ---------------------------------------------------------------------------
+// Param structs
+// ---------------------------------------------------------------------------
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CreateModelProviderParams {
+    pub name: String,
+    pub api_url: String,
+    pub api_key: String,
+    pub agent_types: Vec<String>,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateModelProviderParams {
+    pub id: i32,
+    pub name: Option<String>,
+    pub api_url: Option<String>,
+    pub api_key: Option<String>,
+    pub agent_types: Option<Vec<String>>,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ModelProviderIdParams {
+    pub id: i32,
+}
+
+// ---------------------------------------------------------------------------
+// Handlers
+// ---------------------------------------------------------------------------
+
+pub async fn list_model_providers(
+    Extension(state): Extension<Arc<AppState>>,
+) -> Result<Json<Vec<ModelProviderInfo>>, AppCommandError> {
+    let result = mp_commands::list_model_providers_core(&state.db).await?;
+    Ok(Json(result))
+}
+
+pub async fn create_model_provider(
+    Extension(state): Extension<Arc<AppState>>,
+    Json(params): Json<CreateModelProviderParams>,
+) -> Result<Json<ModelProviderInfo>, AppCommandError> {
+    let result = mp_commands::create_model_provider_core(
+        &state.db,
+        params.name,
+        params.api_url,
+        params.api_key,
+        params.agent_types,
+    )
+    .await?;
+    Ok(Json(result))
+}
+
+pub async fn update_model_provider(
+    Extension(state): Extension<Arc<AppState>>,
+    Json(params): Json<UpdateModelProviderParams>,
+) -> Result<Json<ModelProviderInfo>, AppCommandError> {
+    let result = mp_commands::update_model_provider_core(
+        &state.db,
+        params.id,
+        params.name,
+        params.api_url,
+        params.api_key,
+        params.agent_types,
+    )
+    .await?;
+    Ok(Json(result))
+}
+
+pub async fn delete_model_provider(
+    Extension(state): Extension<Arc<AppState>>,
+    Json(params): Json<ModelProviderIdParams>,
+) -> Result<Json<()>, AppCommandError> {
+    mp_commands::delete_model_provider_core(&state.db, params.id).await?;
+    Ok(Json(()))
+}