feat(v1.1.1-routes): outbox-routed sync HTTP + dispatch_mode=async

Routes gain `dispatch_mode TEXT NOT NULL DEFAULT 'sync'` (migration
0012). Existing routes default to sync so the migration is
non-breaking. `DispatchMode` enum lands in `picloud-shared`.

The user-routes orchestrator handler now branches:
- `dispatch_mode = async` → write outbox row with `reply_to = None`,
  return `202 Accepted` + `{accepted_at, execution_id}`. Dispatcher
  fires the script in the background; retries / dead-letters via
  the framework from commit 5.
- `dispatch_mode = sync` → register an inbox channel
  (`tokio::sync::oneshot`), write outbox row with `reply_to =
  inbox_id`, `.await` on the receiver with a timeout =
  script.timeout_seconds + 2s buffer. Dispatcher hands the result
  back; orchestrator maps `InboxResult` into the HTTP response per
  the design-notes §3 status-code table (422/502/503/504/507/500).

`InboxRegistry` (orchestrator-core/src/inbox.rs) is the in-process
implementation of `InboxResolver`. Lock-free HashMap of pending
oneshot senders keyed by `inbox_id`. Tests cover register/deliver
round-trip, unknown-id is abandoned, dropped-receiver is abandoned,
explicit cancel. Cluster mode (v1.3+) swaps this for
LISTEN/NOTIFY-keyed lookup behind the same trait.

`OutboxWriter` trait lives in `picloud-shared` so orchestrator-core
can write to the outbox without depending on manager-core (which
would invert the dependency arrow). `PostgresOutboxRepo` implements
both `OutboxRepo` (dispatcher surface) and `OutboxWriter`
(orchestrator surface); the picloud binary clones the same concrete
Arc into both trait views.

The dispatcher's HTTP arm (commit 5 had a stub) now decodes the
`HttpDispatchPayload` off the outbox row, looks up the script,
synthesizes an `ExecRequest`, and runs it through the executor.
Outcome routing reuses the same path as KV triggers — sync HTTP
flows through the inbox, async dispatch gets dropped after
success (or DL'd on exhaustion).

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

crates/manager-core/src/outbox_repo.rs

@@ -5,7 +5,10 @@
 
 use async_trait::async_trait;
 use chrono::{DateTime, Utc};
-use picloud_shared::{AdminUserId, AppId, ExecutionId, ScriptId, TriggerId};
+use picloud_shared::{
+    AdminUserId, AppId, ExecutionId, NewHttpOutbox, OutboxWriter, OutboxWriterError, ScriptId,
+    TriggerId,
+};
 use sqlx::PgPool;
 use uuid::Uuid;
 
@@ -195,6 +198,28 @@ impl OutboxRepo for PostgresOutboxRepo {
     }
 }
 
+/// `OutboxWriter` implementation so orchestrator-core (which can't
+/// depend on manager-core) can enqueue HTTP outbox rows through the
+/// shared trait.
+#[async_trait]
+impl OutboxWriter for PostgresOutboxRepo {
+    async fn enqueue_http(&self, row: NewHttpOutbox) -> Result<Uuid, OutboxWriterError> {
+        self.insert(NewOutboxRow {
+            app_id: row.app_id,
+            source_kind: OutboxSourceKind::Http,
+            trigger_id: Some(TriggerId::from(row.route_id)),
+            script_id: Some(row.script_id),
+            reply_to: row.reply_to,
+            payload: row.payload,
+            origin_principal: row.origin_principal,
+            trigger_depth: row.trigger_depth,
+            root_execution_id: row.root_execution_id,
+        })
+        .await
+        .map_err(|e| OutboxWriterError::Backend(e.to_string()))
+    }
+}
+
 #[derive(sqlx::FromRow)]
 struct OutboxRowRaw {
     id: Uuid,