feat(picloud): opportunistic principal middleware on the data plane

The data-plane (POST /execute/{id} + user-route fallback) is
unauthenticated by default — public scripts get hit by anonymous HTTP
traffic. But some calls are authed (dashboard test-runs, API-key
invocations) and v1.1.x services will want to see the caller via
`cx.principal` for audit / authz once those features land.

  - New manager-core::attach_principal_if_present middleware. Always
    inserts Extension<Option<Principal>>: Some on resolved bearer/cookie,
    None on absent or malformed token. Fail-open on DB blip so a
    transient infra failure can't 500 anonymous traffic.
  - Wired in picloud build_app, scoped to the data-plane and user-routes
    routers only. The admin path keeps using require_authenticated; no
    double-resolve on the same token.
  - orchestrator-core handlers (execute_by_id, user_route_handler) now
    extract Extension<Option<Principal>> and pass it to build_exec_request.
    Replaces the temporary `None` placeholders from the previous commit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/orchestrator-core/src/api.rs

@@ -12,7 +12,7 @@ use axum::{
     http::{HeaderMap, HeaderName, HeaderValue, StatusCode},
     response::{IntoResponse, Response},
     routing::post,
-    Json, Router,
+    Extension, Json, Router,
 };
 use chrono::Utc;
 use picloud_executor_core::{ExecError, ExecRequest, ExecResponse, InvocationType};
@@ -55,6 +55,11 @@ impl<E, R> Clone for DataPlaneState<E, R> {
 
 /// Build the data-plane router. Handles `POST /execute/:id` — the
 /// always-available ID-based bypass.
+///
+/// Handlers expect an `Extension<Option<Principal>>` to be attached by
+/// upstream middleware (`manager-core::attach_principal_if_present`);
+/// requests without that extension panic at extraction time. The
+/// picloud binary wires this in `build_app`.
 pub fn data_plane_router<E, R>(state: DataPlaneState<E, R>) -> Router
 where
     E: ExecutorClient + 'static,
@@ -68,6 +73,10 @@ where
 /// Build a router that handles ALL paths via the user-defined routing
 /// table. Intended to be merged into the picloud app router as a
 /// fallback (after the system routes are mounted).
+///
+/// Same middleware expectation as `data_plane_router` — wrap with
+/// `attach_principal_if_present` so handlers can extract
+/// `Extension<Option<Principal>>`.
 pub fn user_routes_router<E, R>(state: DataPlaneState<E, R>) -> Router
 where
     E: ExecutorClient + 'static,
@@ -85,6 +94,7 @@ where
 async fn execute_by_id<E, R>(
     State(state): State<DataPlaneState<E, R>>,
     Path(id): Path<ScriptId>,
+    Extension(principal): Extension<Option<Principal>>,
     headers: HeaderMap,
     body: Bytes,
 ) -> Result<Response, ApiError>
@@ -98,10 +108,7 @@ where
         .await?
         .ok_or(ApiError::NotFound(id))?;
 
-    // Principal stays `None` until the data-plane `attach_principal_if_present`
-    // middleware lands in the picloud-wiring commit. Both shapes are
-    // valid against `ExecRequest.principal: Option<Principal>`.
-    let mut req = build_exec_request(id, &script.name, &headers, &body, script.app_id, None)?;
+    let mut req = build_exec_request(id, &script.name, &headers, &body, script.app_id, principal)?;
     req.sandbox_overrides = script.sandbox;
     let request_id = req.request_id;
     let request_path = req.path.clone();
@@ -137,6 +144,7 @@ where
 
 async fn user_route_handler<E, R>(
     State(state): State<DataPlaneState<E, R>>,
+    Extension(principal): Extension<Option<Principal>>,
     request: Request,
 ) -> Result<Response, ApiError>
 where
@@ -200,7 +208,7 @@ where
         &headers,
         &body_bytes,
         app_id,
-        None,
+        principal,
     )?;
     req.path = path;
     req.params = matched.params;