feat: async SunbeamClient factory with unified auth resolution

SunbeamClient accessors are now async and resolve auth per-client:
- SSO bearer (get_token) for admin APIs, Matrix, La Suite, OpenSearch
- Gitea PAT (get_gitea_token) for VCS
- None for Prometheus, Loki, S3, LiveKit

Fixes client URLs to match deployed routes: hydra→hydra.{domain},
matrix→messages.{domain}, grafana→metrics.{domain},
prometheus→systemmetrics.{domain}, loki→systemlogs.{domain}.

Removes all ad-hoc token helpers from CLI modules (matrix_with_token,
os_client, people_client, etc). Every dispatch just calls
client.service().await?.

sunbeam-sdk/src/matrix/cli.rs

@@ -1,22 +1,10 @@
 //! CLI dispatch for Matrix chat commands.
 
+use crate::client::SunbeamClient;
 use crate::error::Result;
 use crate::output::{self, OutputFormat};
 use clap::Subcommand;
 
-// ---------------------------------------------------------------------------
-// Auth helper
-// ---------------------------------------------------------------------------
-
-/// Construct a [`MatrixClient`] with a valid access token from the credential
-/// cache. Fails if the user is not logged in.
-async fn matrix_with_token(domain: &str) -> Result<super::MatrixClient> {
-    let token = crate::auth::get_token().await?;
-    let mut m = super::MatrixClient::connect(domain);
-    m.set_token(&token);
-    Ok(m)
-}
-
 // ---------------------------------------------------------------------------
 // Command tree
 // ---------------------------------------------------------------------------
@@ -343,8 +331,8 @@ pub enum UserAction {
 // ---------------------------------------------------------------------------
 
 /// Dispatch a parsed [`ChatCommand`] against the Matrix homeserver.
-pub async fn dispatch(domain: &str, format: OutputFormat, cmd: ChatCommand) -> Result<()> {
-    let m = matrix_with_token(domain).await?;
+pub async fn dispatch(client: &SunbeamClient, format: OutputFormat, cmd: ChatCommand) -> Result<()> {
+    let m = client.matrix().await?;
 
     match cmd {
         // -- Whoami ---------------------------------------------------------