feat(cli): add MCP management subcommand with add/list/remove commands

Introduce `McpCommand` enum and handlers in `owlen-cli` to manage MCP server registrations, including adding, listing, and removing servers across configuration scopes. Add scoped configuration support (`ScopedMcpServer`, `McpConfigScope`) and OAuth token handling in core config, alongside runtime refresh of MCP servers. Implement toast notifications in the TUI (`render_toasts`, `Toast`, `ToastLevel`) and integrate async handling for session events. Update config loading, validation, and schema versioning to accommodate new MCP scopes and resources. Add `httpmock` as a dev dependency for testing.

crates/owlen-core/src/mcp/remote_client.rs

@@ -12,6 +12,7 @@ use anyhow::anyhow;
 use futures::{StreamExt, future::BoxFuture, stream};
 use reqwest::Client as HttpClient;
 use serde_json::json;
+use std::collections::HashMap;
 use std::path::Path;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicU64, Ordering};
@@ -39,6 +40,15 @@ pub struct RemoteMcpClient {
     ws_endpoint: Option<String>,
     // Incrementing request identifier.
     next_id: AtomicU64,
+    // Optional HTTP header (name, value) injected into every request.
+    http_header: Option<(String, String)>,
+}
+
+/// Runtime secrets provided when constructing an MCP client.
+#[derive(Debug, Default, Clone)]
+pub struct McpRuntimeSecrets {
+    pub env_overrides: HashMap<String, String>,
+    pub http_header: Option<(String, String)>,
 }
 
 impl RemoteMcpClient {
@@ -48,6 +58,14 @@ impl RemoteMcpClient {
     /// Spawn an external MCP server based on a configuration entry.
     /// The server must communicate over STDIO (the only supported transport).
     pub fn new_with_config(config: &crate::config::McpServerConfig) -> Result<Self> {
+        Self::new_with_runtime(config, None)
+    }
+
+    pub fn new_with_runtime(
+        config: &crate::config::McpServerConfig,
+        runtime: Option<McpRuntimeSecrets>,
+    ) -> Result<Self> {
+        let mut runtime = runtime.unwrap_or_default();
         let transport = config.transport.to_lowercase();
         match transport.as_str() {
             "stdio" => {
@@ -64,6 +82,9 @@ impl RemoteMcpClient {
                 for (k, v) in config.env.iter() {
                     cmd.env(k, v);
                 }
+                for (k, v) in runtime.env_overrides.drain() {
+                    cmd.env(k, v);
+                }
 
                 let mut child = cmd.spawn().map_err(|e| {
                     Error::Io(std::io::Error::new(
@@ -92,6 +113,7 @@ impl RemoteMcpClient {
                     ws_stream: None,
                     ws_endpoint: None,
                     next_id: AtomicU64::new(1),
+                    http_header: None,
                 })
             }
             "http" => {
@@ -109,6 +131,7 @@ impl RemoteMcpClient {
                     ws_stream: None,
                     ws_endpoint: None,
                     next_id: AtomicU64::new(1),
+                    http_header: runtime.http_header.take(),
                 })
             }
             "websocket" => {
@@ -132,6 +155,7 @@ impl RemoteMcpClient {
                     ws_stream: Some(Arc::new(Mutex::new(ws_stream))),
                     ws_endpoint: Some(ws_url),
                     next_id: AtomicU64::new(1),
+                    http_header: runtime.http_header.take(),
                 })
             }
             other => Err(Error::NotImplemented(format!(
@@ -171,6 +195,7 @@ impl RemoteMcpClient {
             args: Vec::new(),
             transport: "stdio".to_string(),
             env: std::collections::HashMap::new(),
+            oauth: None,
         };
         Self::new_with_config(&config)
     }
@@ -193,8 +218,11 @@ impl RemoteMcpClient {
                 .http_endpoint
                 .as_ref()
                 .ok_or_else(|| Error::Network("Missing HTTP endpoint".into()))?;
-            let resp = client
-                .post(endpoint)
+            let mut builder = client.post(endpoint);
+            if let Some((ref header_name, ref header_value)) = self.http_header {
+                builder = builder.header(header_name, header_value);
+            }
+            let resp = builder
                 .json(&request)
                 .send()
                 .await