S3CSI-227: Move volumeID from Labels to Annotations and add cache volume context

[anurag4DSB]

Summary

• Move VolumeID/PV name from Labels to Annotations to fix 63-character label overflow
• Add cache volume context constants for upstream parity
• Keep deprecated label constants for backward compatibility

Changes

• pkg/podmounter/mppod/mppod.go: Add annotation constants, deprecate old labels
• pkg/podmounter/mppod/creator.go: Write to Annotations, keep deprecated labels
• pkg/podmounter/mppod/creator_test.go: Assert annotations contain volume name
• pkg/driver/node/mounter/pod_unmounter.go: Read annotations first, fall back to labels
• pkg/driver/node/mounter/pod_unmounter_test.go: Updated for deprecated label constants
• pkg/driver/node/volumecontext/volume_context.go: Add cache constants
• tests/controller/controller_test.go: Updated for annotation-based assertions

Test Plan

• Unit test: Creator puts volume name in Annotations, not Labels
• Unit test: Unmounter reads annotations first, falls back to deprecated labels
• Unit test: Controller tests verify annotation-based pod verification
• GOOS=linux go vet passes
• CI E2E: Dynamic provisioning generates PV names exercising annotation path. Cache suite validates cache constants. Unmount path tested during every E2E cleanup.

Issue: S3CSI-227

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.98%. Comparing base (75ee0ef) to head (bce046c).
✅ All tests successful. No failed tests found.

Additional details and impacted files

Files with missing lines	Coverage Δ
pkg/driver/node/mounter/pod_unmounter.go	77.44% <100.00%> (+0.52%)	⬆️
pkg/podmounter/mppod/creator.go	96.72% <100.00%> (+0.14%)	⬆️
pkg/podmounter/mppod/mppod.go	100.00% <ø> (ø)

@@            Coverage Diff             @@
##             main     #327      +/-   ##
==========================================
+ Coverage   71.89%   71.98%   +0.08%     
==========================================
  Files          47       47              
  Lines        2669     2677       +8     
==========================================
+ Hits         1919     1927       +8     
  Misses        622      622              
  Partials      128      128