feat: Add time field to abbreviated metadata for pnpm time-based resolution (#834)

- [x] Add time field to abbreviated manifests in
`_listPackageAbbreviatedManifests` method
- [x] Fix cache update logic to populate time field when adding versions
to abbreviated manifests
- [x] Fix cache update logic to remove time field when removing versions
from abbreviated manifests
- [x] Add comprehensive test coverage for time field in abbreviated
manifests
- [x] All tests passing (30/30 in ShowPackageController.test.ts)

closes https://github.com/cnpm/cnpmcore/issues/609

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Package metadata now consistently includes time information (created,
modified, and per-version publish timestamps) in both full and
abbreviated manifests.
* Removing a version also removes its corresponding time entry to keep
metadata accurate.
* Added guards to prevent writing invalid time data, improving
stability.

* **Tests**
* Added tests to verify presence and correctness of time fields in
abbreviated manifests, including created/modified and per-version
timestamps.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: fengmk2 <156269+fengmk2@users.noreply.github.com>
Co-authored-by: MK (fengmk2) <fengmk2@gmail.com>

app/core/service/PackageManagerService.ts

@@ -925,6 +925,11 @@ export class PackageManagerService extends AbstractService {
           if (abbreviatedManifest) {
             abbreviatedManifests.versions[packageVersion.version] =
               abbreviatedManifest;
+            // abbreviatedManifests.time is guaranteed to exist since it's initialized in _listPackageAbbreviatedManifests
+            if (abbreviatedManifests.time) {
+              abbreviatedManifests.time[packageVersion.version] =
+                packageVersion.publishTime;
+            }
           }
         }
       }
@@ -937,6 +942,8 @@ export class PackageManagerService extends AbstractService {
         delete fullManifests.time[version];
         // eslint-disable-next-line typescript-eslint/no-dynamic-delete
         delete abbreviatedManifests.versions[version];
+        // eslint-disable-next-line typescript-eslint/no-dynamic-delete
+        delete abbreviatedManifests.time?.[version];
       }
     }
 
@@ -1357,6 +1364,10 @@ export class PackageManagerService extends AbstractService {
       modified: pkg.updatedAt,
       name: pkg.fullname,
       versions: {},
+      time: {
+        created: pkg.createdAt,
+        modified: pkg.updatedAt,
+      },
     };
 
     for (const packageVersion of packageVersions) {
@@ -1366,6 +1377,10 @@ export class PackageManagerService extends AbstractService {
         );
       if (manifest) {
         data.versions[packageVersion.version] = manifest;
+        // data.time is guaranteed to exist since we initialize it above
+        if (data.time) {
+          data.time[packageVersion.version] = packageVersion.publishTime;
+        }
       }
     }
     return data;

test/port/controller/package/ShowPackageController.test.ts

@@ -384,6 +384,34 @@ describe('test/port/controller/package/ShowPackageController.test.ts', () => {
         .expect(201);
     });
 
+    it('should include time field in abbreviated manifests for pnpm time-based resolution', async () => {
+      mock(app.config.cnpmcore, 'syncMode', 'all');
+      const res = await app
+        .httpRequest()
+        .get(`/${name}`)
+        .set('Accept', 'application/vnd.npm.install-v1+json')
+        .expect(200)
+        .expect('content-type', 'application/json; charset=utf-8');
+      const pkg = res.body;
+      
+      // Verify time field structure exists
+      assert.ok(pkg.time, 'time field should be present in abbreviated manifests');
+      assert.ok(pkg.time.created, 'time.created should be present');
+      assert.ok(pkg.time.modified, 'time.modified should be present');
+      
+      // Verify each version has a publish time
+      const versions = Object.keys(pkg.versions);
+      for (const version of versions) {
+        assert.ok(pkg.time[version], `time.${version} should be present for version ${version}`);
+        assert.ok(pkg.time[version] instanceof Date || typeof pkg.time[version] === 'string', 
+          `time.${version} should be a Date or string`);
+      }
+      
+      // Verify at least the expected versions have time entries
+      assert.ok(pkg.time['1.0.0'], 'time.1.0.0 should be present');
+      assert.ok(pkg.time['2.0.0'], 'time.2.0.0 should be present');
+    });
+
     it('should show one scoped package with abbreviated manifests', async () => {
       const res = await app
         .httpRequest()