chore: switch restore ops to cluster restore API

[leon-ape]

Summary

Switch restore ops to the new Cluster restore API and remove the old annotation-based restore plumbing.

Changes

• Make restore ops build target Clusters with spec.restore.
• Make restore ops wait on apps restore condition plus final Cluster phase.
• Stop writing kubeblocks.io/restore-from-backup.
• Remove old restore annotation constants, backup source target bridge, and dead restore-manager annotation parsing.
• Keep h-scale behavior conservative: single backup target can be inferred, multi-target backups fail fast with a TODO for explicit source target selection.
• Update restore examples to use Cluster.spec.restore.

Not included

• No new public API.
• No apps restore intent projection changes.
• No dataprotection Backup-kind PVC runtime changes.

Validation

• make generate
• make manifests
• make doc
• make fmt
• make lint
• KUBEBUILDER_ASSETS="/Users/leon/Library/Application Support/io.kubebuilder.envtest/k8s/1.26.1-darwin-arm64" go test ./pkg/operations -run TestAPIs
• KUBEBUILDER_ASSETS="/Users/leon/Library/Application Support/io.kubebuilder.envtest/k8s/1.26.1-darwin-arm64" go test ./pkg/controller/plan
• KUBEBUILDER_ASSETS="/Users/leon/Library/Application Support/io.kubebuilder.envtest/k8s/1.26.1-darwin-arm64" go test ./controllers/dataprotection ./controllers/apps/cluster/... ./controllers/apps/component/...

Diff audit

Compared with the original large branch, the stacked result only differs by generated InstanceSet CRD/API docs from make manifests/doc, a test-only removal of a DP constant import from pkg/controllerutil/volume_util_test.go, and deletion of the unused dataprotection.kubeblocks.io/volume-source parameter.

[codecov]

Codecov Report

❌ Patch coverage is 67.64706% with 33 lines in your changes missing coverage. Please review.
✅ Project coverage is 52.65%. Comparing base (3a0cd73) to head (5b8cfb5).

Files with missing lines	Patch %	Lines
pkg/operations/restore.go	81.17%	10 Missing and 6 partials ⚠️
pkg/controller/plan/restore.go	0.00%	13 Missing ⚠️
pkg/operations/horizontal_scaling.go	0.00%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@                        Coverage Diff                        @@
##           support/dp-backup-pvc-restore   #10246      +/-   ##
=================================================================
- Coverage                          53.03%   52.65%   -0.39%     
=================================================================
  Files                                533      533              
  Lines                              62596    62498      -98     
=================================================================
- Hits                               33200    32910     -290     
- Misses                             25998    26219     +221     
+ Partials                            3398     3369      -29     

Flag	Coverage Δ
unittests	52.65% <67.64%> (-0.39%)	⬇️

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