Add job_event and job_event_ack to the gateway protocol

A gateway keeps what happened to a job it was handed (started, finished,
failed) and re-sends it on every connection until the cloud acknowledges
it, so an outcome reached while the cloud was unreachable still arrives.

packages/ts-types/src/schemas/edge.ts

@@ -316,6 +316,22 @@ export const EdgeClientMessageSchema = Type.Union([
     jpeg_base64: Maybe(Type.String()),
     error: Maybe(Type.String()),
   }),
+  /**
+   * What happened to a job the gateway was handed. Kept in the gateway's own
+   * database and re-sent on every connection until answered with a
+   * `job_event_ack`; the cloud applies it only to a job still in flight and
+   * applying it twice changes nothing.
+   */
+  Type.Object({
+    type: Type.Literal("job_event"),
+    event_id: Type.Integer(),
+    job_id: Type.String({ format: "uuid" }),
+    event: Type.Union([Type.Literal("started"), Type.Literal("finished"), Type.Literal("failed")]),
+    /** For `failed`: the reason, in words for an operator. */
+    detail: Maybe(Type.String()),
+    /** When the gateway saw it, ms since the Unix epoch. */
+    at_ms: Type.Integer(),
+  }),
   Type.Object({
     type: Type.Literal("frame_batch"),
     printer_id: Type.String(),
@@ -401,6 +417,14 @@ export const EdgeServerMessageSchema = Type.Union([
     },
     { additionalProperties: false },
   ),
+  /** The cloud has dealt with a `job_event`; the gateway can forget it. */
+  Type.Object(
+    {
+      type: Type.Literal("job_event_ack"),
+      event_id: Type.Integer(),
+    },
+    { additionalProperties: false },
+  ),
   Type.Object({
     type: Type.Literal("command"),
     command_id: Type.String(),