Merge main: resolve conflicts with capacity_type rename

Resolve merge conflicts from upstream preemptible→capacity_type rename.
Update all tpu_pools YAML configs and test fixtures to use the new
capacity_type field. Regenerate protobuf files.

Author: rjpower

.agents/skills/architecture/SKILL.md

@@ -57,8 +57,7 @@ marin/
 ├── docs/                       # Documentation (tutorials/, explanations/, references/, recipes/, reports/, design/, dev-guide/, model-cards/)
 ├── infra/                      # Ray cluster configs (marin-*.yaml, configure_gcp_registry.py)
 ├── scripts/                    # Utilities (ray/, training/, pm/, debug/, gpu_eval/)
-├── docker/                     # Docker configs (marin/, levanter/)
-└── data_browser/               # Web UI (server.py, src/, conf/)
+└── docker/                     # Docker configs (marin/, levanter/)
 ```
 
 ## Key Concepts

.github/workflows/nightshift-cleanup.yml

@@ -12,7 +12,7 @@ concurrency:
 jobs:
   cleanup:
     runs-on: ubuntu-latest
-    timeout-minutes: 240
+    timeout-minutes: 360
     permissions:
       contents: write
       pull-requests: write