review: comment budget and named func types in pkg/scale and controllers

[CMGS]

Two review-only commits. Behavior is unchanged; the claim path is untouched (no allocation, lock, or control-flow change).

review: comment budget — godoc on interface-implementing methods

Drops godoc that paraphrases the interface the method implements, and condenses the blocks that had grown into justification narrative.

Deleted (the interface documents the contract, and a compile-time check pins the implementation):

• pkg/scale/sandboxstore_lifecycle.go — all seven scatterGatherStore lifecycle methods; SandboxStore/SandboxLifecycle in sandboxstore.go already document them.
• pkg/scale/sandboxstore_impl.go — StaticInventorySource.Apply/ListNodes/NodeInventory/NodeCapacity and ClientInventorySource.ListNodes/NodeInventory/NodeCapacity.
• pkg/scale/claimgateway_impl.go — ReviewAuthorizer.Authorize.
• pkg/scale/warmpool/driver.go — Driver.Reconcile; the requeue-keeps-status-fresh fact is already stated where the predicate is wired in SetupWithManager.
• pkg/scale/apiserver/lifecycle_storage.go — GroupVersionKind and Create.
• pkg/scale/apiserver/storage.go — Create and Delete.

Condensed:

• nodeClaimGateway.Release — the eleven-line contract block becomes three lines stating the invariant.
• sandboxREST.Delete — the delete-authorization invariant survives as one line inside the method body.
• CacheByObject, checkOwnership, v1alpha1State — one line each.

Comment lines: 61 removed, 6 added.

review: named func types

• controllers/sandbox_controller.go spelled func(string) bool four times and func(string) three times across filterSystemKeys, propagateKeys, and prunePropagated. Both are now keyPredicate and keyCallback.
• pkg/scale/sandboxstore_impl.go spelled func(inv *NodeInventory, i int) bool in findEntry and matchOnNode. Both now take inventoryMatch.

No comment lines added or removed.

Gates

Run from the worktree root with GOWORK=off.

make lint            0 issues. (GOOS=linux), 0 issues. (GOOS=darwin)
make fmt-check       clean on GOOS=darwin and GOOS=linux
asl ./...            clean on GOOS=darwin and GOOS=linux
go test -race -count=1 ./...   all packages ok