storage: admit tiered_cloud partitions to space management

tiered_cloud local log segments were never reclaimed by space
management, so a saturating produce workload fills local disk and
cascades to KAFKA_STORAGE_ERROR while legacy tiered storage stays
bounded. The reclaim executor (ctp_stm) and the offset channel
(compute_gc_offset returning a pinned _cloud_gc_offset) already exist;
cloud topics were only gated out of the eviction-policy decision side.

Relax the four is_cloud_retention_active / remote_partition gates to
admit tiered_cloud partitions, bounded by the reconciled L1 offset
(max_removable). Spike for bench validation; the _cloud_gc_offset
clear/refresh semantics for ctp_stm still need work.

Author: oleiman

src/v/resource_mgmt/storage.cc

@@ -289,7 +289,13 @@ eviction_policy::collect_reclaimable_offsets() {
      */
     chunked_vector<ss::lw_shared_ptr<cluster::partition>> partitions;
     for (const auto& p : _pm->local().partitions()) {
-        if (!p.second->remote_partition()) {
+        // SPIKE(space-mgmt): also admit tiered_cloud partitions. Their local
+        // log is a cache bounded by the reconciled (L1) offset; the pinned
+        // _cloud_gc_offset flows to ctp_stm via compute_gc_offset. (cloud mode
+        // already trims to max_removable and ignores the pin, so exclude it.)
+        if (
+          !p.second->remote_partition()
+          && !p.second->log()->config().is_tiered_cloud()) {
             continue;
         }
         partitions.push_back(p.second);

src/v/storage/disk_log_impl.cc

@@ -4279,7 +4279,7 @@ ss::future<usage_report> disk_log_impl::disk_usage(gc_config cfg) {
 chunked_vector<ss::lw_shared_ptr<segment>>
 disk_log_impl::cloud_gc_eligible_segments() {
     vassert(
-      is_cloud_retention_active(),
+      is_cloud_retention_active() || config().is_tiered_cloud(),
       "Expected {} to have cloud retention enabled",
       config().ntp());
 
@@ -4313,7 +4313,7 @@ disk_log_impl::cloud_gc_eligible_segments() {
 }
 
 void disk_log_impl::set_cloud_gc_offset(model::offset offset) {
-    if (!is_cloud_retention_active()) {
+    if (!is_cloud_retention_active() && !config().is_tiered_cloud()) {
         vlog(
           stlog.debug,
           "Ignoring request to set GC offset on non-cloud enabled partition "
@@ -4338,7 +4338,7 @@ disk_log_impl::get_reclaimable_offsets(gc_config cfg) {
 
     reclaimable_offsets res;
 
-    if (!is_cloud_retention_active()) {
+    if (!is_cloud_retention_active() && !config().is_tiered_cloud()) {
         vlog(
           stlog.debug,
           "Reporting no reclaimable offsets for non-cloud partition {}",