feat(PER-9724): send priority on build create via PERCY_PRIORITY (internal) (#2329)

Internal product orchestration (e.g. Scanner / LCA) can set PERCY_PRIORITY=true
to request the priority lane; the client forwards it as the build-create
`priority` attribute. Mirrors the existing PERCY_ORIGINATED_SOURCE internal
signal in createBuild.

percy-api only honors `priority` for eligible internal build types
(visual_scanner / responsive_scanner / lca), so this is a no-op for customer
builds and is not customer-controllable. Attribute is omitted entirely when
PERCY_PRIORITY is unset (no payload change for existing flows).

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: annukumari-bs

packages/client/src/client.js

@@ -326,6 +326,12 @@ export class PercyClient {
 
     let tagsArr = tagsList(this.labels);
 
+    // PER-9724: internal-only priority request. Set by internal product
+    // orchestration (e.g. Scanner / LCA) via PERCY_PRIORITY; mirrors the
+    // PERCY_ORIGINATED_SOURCE internal signal above. percy-api only honors this
+    // for eligible internal build types, so it is a no-op for customer builds.
+    let priority = process.env.PERCY_PRIORITY === 'true';
+
     return this.post('builds', {
       data: {
         type: 'builds',
@@ -351,7 +357,8 @@ export class PercyClient {
           'skip-base-build': this.config.percy?.skipBaseBuild,
           'testhub-build-uuid': this.env.testhubBuildUuid,
           'testhub-build-run-id': this.env.testhubBuildRunId,
-          ...(visualConfig ? { 'visual-config': visualConfig } : {})
+          ...(visualConfig ? { 'visual-config': visualConfig } : {}),
+          ...(priority ? { priority: true } : {})
         },
         relationships: {
           resources: {

packages/client/test/client.test.js

@@ -199,6 +199,7 @@ describe('PercyClient', () => {
       delete process.env.PERCY_AUTO_ENABLED_GROUP_BUILD;
       delete process.env.PERCY_ORIGINATED_SOURCE;
       delete process.env.PERCY_VISUAL_CONFIG;
+      delete process.env.PERCY_PRIORITY;
     });
 
     it('creates a new build', async () => {
@@ -238,6 +239,21 @@ describe('PercyClient', () => {
         }));
     });
 
+    it('sends priority: true when PERCY_PRIORITY is set (internal signal)', async () => {
+      process.env.PERCY_PRIORITY = 'true';
+
+      await client.createBuild();
+
+      expect(api.requests['/builds'][0].body.data.attributes)
+        .toEqual(jasmine.objectContaining({ priority: true }));
+    });
+
+    it('does not send a priority attribute when PERCY_PRIORITY is unset', async () => {
+      await client.createBuild();
+
+      expect(api.requests['/builds'][0].body.data.attributes.priority).toBeUndefined();
+    });
+
     it('creates a new build with projectType passed as null', async () => {
       await expectAsync(client.createBuild({ projectType: null })).toBeResolvedTo({
         data: {