telegram bot user isolation, config store, user context channels

crates/core-api/src/user_channel.rs

@@ -0,0 +1,57 @@
+//! Channel-to-session contract (blueprint §13).
+//!
+//! In the multi-user architecture, chat hubs, approval managers and event
+//! streams are per-user (inside [`UserContext`]). External channels (Telegram,
+//! mobile, …) need a way to resolve a user's owner-bound runtime at runtime,
+//! without depending on the concrete `Skald` / `UserContext` types.
+//!
+//! [`UserChannelApi`] is the lookup seam: given a `user_id`, returns a
+//! [`UserChannelHandle`] when the user's database is unlocked (§9), or `None`
+//! when it is still locked. The handle exposes the per-user [`ChatHubApi`],
+//! [`ApprovalApi`] and event stream — everything a channel adapter needs to
+//! route a message and receive the response events.
+//!
+//! This is the "one contract" of §13: each channel (Telegram, mobile, …) is a
+//! thin adapter over it, so N channel rewrites become 1 contract + N adapters.
+
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use tokio::sync::broadcast;
+
+use crate::approval::ApprovalApi;
+use crate::chat_hub::ChatHubApi;
+use crate::events::GlobalEvent;
+
+/// Resolves an unlocked user's channel handle.
+///
+/// Implemented by the application core (`Skald`) and injected into
+/// [`crate::plugin::PluginContext`] as `user_channel`.
+#[async_trait]
+pub trait UserChannelApi: Send + Sync {
+    /// Returns the user's handle if their database is unlocked in this boot
+    /// (§9: from first login until restart). `None` = locked — the caller
+    /// should prompt the user to log in.
+    async fn resolve_user(&self, user_id: &str) -> Option<Arc<dyn UserChannelHandle>>;
+}
+
+/// Handle to one unlocked user's owner-bound runtime.
+///
+/// Lifetime = the user's pool lifetime (§9). Cloning the returned `Arc`s is
+/// cheap (they share the underlying state). The event receiver obtained from
+/// [`UserChannelHandle::subscribe`] is independent per call — each subscriber
+/// gets every future event.
+pub trait UserChannelHandle: Send + Sync {
+    /// The opaque user id this handle belongs to.
+    fn user_id(&self) -> &str;
+
+    /// The user's chat hub — send messages, manage sessions, query context.
+    fn chat_hub(&self) -> Arc<dyn ChatHubApi>;
+
+    /// The user's approval manager — resolve pending tool-call approvals.
+    fn approval(&self) -> Arc<dyn ApprovalApi>;
+
+    /// Subscribe to the user's server→client event stream.
+    /// Events are scoped to this user; no cross-user leakage.
+    fn subscribe(&self) -> broadcast::Receiver<GlobalEvent>;
+}