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/shared/src/outbox_writer.rs

@@ -0,0 +1,72 @@
+//! `OutboxWriter` — minimal trait the orchestrator-core sync-HTTP path
+//! uses to enqueue rows into the universal trigger outbox. The
+//! manager-core `PostgresOutboxRepo` implements this in addition to
+//! its richer `OutboxRepo` surface; defining it here lets
+//! orchestrator-core depend on the trait without pulling in
+//! manager-core (which would invert the dependency arrow).
+
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use thiserror::Error;
+use uuid::Uuid;
+
+use crate::{AdminUserId, AppId, ExecutionId, ScriptId};
+
+/// What the orchestrator hands to the outbox when it ingests an HTTP
+/// request. Carries enough for the dispatcher to reconstruct the
+/// `ExecRequest` end-to-end.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct NewHttpOutbox {
+    pub app_id: AppId,
+    /// `routes.id` of the matched route. Discriminated against
+    /// `triggers.id` by `source_kind = 'http'` on the outbox row.
+    pub route_id: Uuid,
+    /// Pre-resolved script so the dispatcher doesn't re-look it up.
+    pub script_id: ScriptId,
+    /// `Some(inbox_id)` for sync HTTP (the orchestrator awaits a
+    /// channel keyed on this id). `None` for `dispatch_mode = async`
+    /// — dispatcher fires-and-forgets, no reply path.
+    pub reply_to: Option<Uuid>,
+    /// Serialized `HttpDispatchPayload` (defined below) — everything
+    /// the dispatcher needs to reconstruct an `ExecRequest`.
+    pub payload: serde_json::Value,
+    /// The principal that ingressed the HTTP request (Some when
+    /// authenticated, None for public). Forensic only; the script
+    /// executes as the route's app principal model, not this.
+    pub origin_principal: Option<AdminUserId>,
+    /// `0` for direct HTTP ingress; the dispatcher will increment
+    /// for any further fan-out triggered by the script.
+    pub trigger_depth: u32,
+    pub root_execution_id: Option<ExecutionId>,
+}
+
+/// The shape the orchestrator serializes into `NewHttpOutbox.payload`
+/// (the JSONB column). Mirrored on the dispatcher side so it can
+/// rebuild an `ExecRequest`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct HttpDispatchPayload {
+    pub script_name: String,
+    pub path: String,
+    pub method: String,
+    pub headers: std::collections::BTreeMap<String, String>,
+    pub body: serde_json::Value,
+    pub params: std::collections::BTreeMap<String, String>,
+    pub query: std::collections::BTreeMap<String, String>,
+    pub rest: String,
+    pub timeout_seconds: u32,
+}
+
+#[async_trait]
+pub trait OutboxWriter: Send + Sync {
+    /// Insert a sync- or async-HTTP outbox row. Returns the row's id
+    /// — the orchestrator stores it locally for forensics and to
+    /// correlate `abandoned_executions` rows when the dispatcher's
+    /// inbox delivery fails.
+    async fn enqueue_http(&self, row: NewHttpOutbox) -> Result<Uuid, OutboxWriterError>;
+}
+
+#[derive(Debug, Error)]
+pub enum OutboxWriterError {
+    #[error("outbox write failed: {0}")]
+    Backend(String),
+}