feat: enrich Segment events with starter context from config

Persist the `starter` field in slicemachine.config.json during init
when `--starter` is used, and auto-enrich all Segment events with it
in TelemetryManager.track(). This lets us track migration funnel
progression (e.g. changes:pushed) for projects originating from the
agentic-migration-starter.

Made-with: Cursor

Author: levimykel

packages/init/src/SliceMachineInitProcess.ts

@@ -1084,6 +1084,9 @@ ${chalk.cyan("?")} Your Prismic repository name`.replace("\n", ""),
 								...config,
 								repositoryName: this.context.repository.domain,
 								adapter: this.context.framework.adapterName,
+								...(this.options.starter
+									? { starter: this.options.starter }
+									: {}),
 							},
 						});
 						parentTask.title = "Updated Slice Machine configuration";
@@ -1098,6 +1101,9 @@ ${chalk.cyan("?")} Your Prismic repository name`.replace("\n", ""),
 								repositoryName: this.context.repository.domain,
 								adapter: this.context.framework.adapterName,
 								libraries: ["./slices"],
+								...(this.options.starter
+									? { starter: this.options.starter }
+									: {}),
 							},
 							path: sliceMachineConfigPath,
 						});

packages/manager/src/lib/decodeSliceMachineConfig.ts

@@ -27,6 +27,7 @@ const SliceMachineConfigCodec = t.intersection([
 		localSliceSimulatorURL: t.string,
 		plugins: t.array(SliceMachineConfigPluginRegistrationCodec),
 		labs: t.partial({ legacySliceUpgrader: t.boolean }),
+		starter: t.string,
 	}),
 ]);
 

packages/manager/src/managers/telemetry/TelemetryManager.ts

@@ -111,6 +111,14 @@ export class TelemetryManager extends BaseManager {
 			}
 		}
 
+		let starter: string | undefined;
+		try {
+			const config = await this.project.getSliceMachineConfig();
+			starter = config.starter;
+		} catch {
+			// noop, happen only when the user is not in a project
+		}
+
 		let environmentKind: Environment["kind"] | "_unknown" | undefined =
 			undefined;
 		if (_includeEnvironmentKind) {
@@ -150,6 +158,7 @@ export class TelemetryManager extends BaseManager {
 			properties: {
 				nodeVersion: process.versions.node,
 				environmentKind,
+				starter,
 				...properties,
 			},
 			context: { ...this._context },

packages/manager/src/types.ts

@@ -32,6 +32,7 @@ export type SliceMachineConfig = {
 	adapter: SliceMachineConfigPluginRegistration;
 	plugins?: SliceMachineConfigPluginRegistration[];
 	labs?: { legacySliceUpgrader?: boolean };
+	starter?: string;
 };
 
 export type OnlyHookErrors<

packages/plugin-kit/src/lib/decodeSliceMachineConfig.ts

@@ -27,6 +27,7 @@ const SliceMachineConfigCodec = t.intersection([
 		localSliceSimulatorURL: t.string,
 		plugins: t.array(SliceMachineConfigPluginRegistrationCodec),
 		labs: t.partial({ legacySliceUpgrader: t.boolean }),
+		starter: t.string,
 	}),
 ]);
 

packages/plugin-kit/src/types.ts

@@ -70,6 +70,7 @@ export type SliceMachineConfig = {
 	adapter: SliceMachineConfigPluginRegistration;
 	plugins?: SliceMachineConfigPluginRegistration[];
 	labs?: { legacySliceUpgrader?: boolean };
+	starter?: string;
 };
 
 /**