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/route_admin.rs

@@ -77,6 +77,12 @@ pub struct CreateRouteRequest {
     pub path_kind: PathKind,
     pub path: String,
     pub method: Option<String>,
+    /// Per-route dispatch mode (v1.1.1). Defaults to `Sync` when
+    /// omitted so older clients aren't broken. `Async` routes return
+    /// `202 Accepted` immediately and run the script in the
+    /// background via the dispatcher.
+    #[serde(default)]
+    pub dispatch_mode: picloud_shared::DispatchMode,
 }
 
 #[derive(Debug, Deserialize)]
@@ -211,6 +217,7 @@ async fn create_route<RR: RouteRepository, SR: ScriptRepository>(
             path_kind: input.path_kind,
             path: normalized_path,
             method: input.method,
+            dispatch_mode: input.dispatch_mode,
         })
         .await?;
     refresh_table(&state).await?;
@@ -370,6 +377,7 @@ pub fn compile_routes(rows: &[Route]) -> Result<Vec<CompiledRoute>, pattern::Par
                 host: pattern::parse_host(r.host_kind, &r.host, r.host_param_name.as_deref())?,
                 path: pattern::parse_path(r.path_kind, &r.path)?,
                 method: r.method.clone(),
+                dispatch_mode: r.dispatch_mode,
             })
         })
         .collect()