huskies: merge 1218 story Remembered/sticky permission approvals so constrained agents stop re-prompting for the same action class

server/src/http/mcp/session.rs

@@ -0,0 +1,51 @@
+//! Task-local session identifier for the requesting MCP client.
+//!
+//! Threaded ambiently through tool dispatch (same pattern as
+//! [`super::progress::EMITTER`]) so a deeply-nested handler — currently only
+//! `tool_prompt_permission` — can scope decisions per requesting agent
+//! without adding a parameter to `dispatch_tool_call` and every one of its
+//! ~40 match arms.
+//!
+//! The HTTP MCP handler installs the scope before dispatching a `tools/call`
+//! request, populated from the `X-Huskies-Session` header that per-story
+//! worktrees embed in their `.mcp.json` (see `worktree::write_mcp_json`).
+//! Callers with no header (the main interactive chat CLI, API-based runtimes
+//! that invoke `dispatch_tool_call` directly) fall back to a fixed
+//! `"default"` key — there is only ever one such session per server process,
+//! so no cross-story leakage results from sharing that bucket.
+
+/// Session key used when no `X-Huskies-Session` header was present.
+pub const DEFAULT_SESSION: &str = "default";
+
+tokio::task_local! {
+    /// Set by the MCP HTTP handler before dispatching a `tools/call` request.
+    /// Unset in tests and in non-HTTP dispatch paths, where [`current`] falls
+    /// back to [`DEFAULT_SESSION`].
+    pub static SESSION_ID: String;
+}
+
+/// Return the current request's session id, or [`DEFAULT_SESSION`] if no
+/// scope is installed.
+pub fn current() -> String {
+    SESSION_ID
+        .try_with(Clone::clone)
+        .unwrap_or_else(|_| DEFAULT_SESSION.to_string())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn current_falls_back_to_default_without_scope() {
+        assert_eq!(current(), DEFAULT_SESSION);
+    }
+
+    #[tokio::test]
+    async fn current_reads_installed_scope() {
+        let value = SESSION_ID
+            .scope("1218".to_string(), async { current() })
+            .await;
+        assert_eq!(value, "1218");
+    }
+}