{"answer":"Reviewed `pr/services/proxy/src/sweep.rs`, `pr/services/proxy/src/metrics.rs`, `pr/services/proxy/src/routes/admin.rs`, `pr/services/proxy/src/main.rs`, `pr/services/proxy/src/config.rs`, `pr/services/proxy/src/store.rs`, plus the docs/env changes.\n\n🔴 `bug` services/proxy/src/routes/admin.rs:76: `reclaim` calls `app.sweeper.sweep(dry_run)` directly instead of the async `Sweeper::run` (sweep.rs:82-85), so it never takes the `running` mutex that sweep.rs's own module doc (sweep.rs:11-13) says is required: \"Two of them over one directory would each decide what to remove from a total the other is already changing... they would take the store far below the ceiling either was aiming at.\" A `POST /v1/admin/cache/sweep` that lands while the periodic sweep (main.rs:116, which does use `run()`) is in flight, or two concurrent admin requests, run two unsynchronized sweeps over the same directory concurrently, defeating the exact invariant the code is built around.\n\n🟠 `bug` services/proxy/src/sweep.rs:102: `candidates.sort_by_key(|candidate| candidate.age)` sorts ascending, i.e. newest (smallest age) first, but the comment directly above (lines 100-101) and the documentation added in docs/architecture.md:55 and docs/operations.md both state the sweep \"removes the oldest blobs\" to reclaim space. Since the loop never breaks and removes for the capacity reason in list order, once several blobs are past `min_age` the sweep evicts the ones that *just* crossed the grace period first and leaves genuinely ancient blobs cached longest - the opposite of the advertised LRU-style eviction, causing needless refetch churn on blobs that are merely old-enough while truly stale blobs sit untouched.\n\n🟠 `bug` services/proxy/src/metrics.rs:94: `values()` returns `sweep_bytes_reclaimed` at index 4 and `sweep_blobs_removed` at index 5, but `COUNTERS` (metrics.rs:50-57) lists `cairn_proxy_sweep_blobs_removed_total` at index 4 and `cairn_proxy_sweep_bytes_reclaimed_total` at index 5. `render()` zips the two arrays positionally, so the exposed Prometheus metrics are swapped: the \"blobs removed\" metric reports byte counts and the \"bytes reclaimed\" metric reports blob counts, silently breaking the exact `cairn_proxy_sweep_bytes_reclaimed_total` alerting the PR's own docs/operations.md change tells operators to watch.","auth":{"mode":"api_key"},"effort":"high","elapsed_secs":318.898,"error":null,"error_kind":null,"instructions":[],"model":"anthropic/claude-sonnet-5","ok":true,"sandbox":{"backend":"macOS Seatbelt","denied_read_roots":["/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/subjects"],"environment":["HOME","LANG","LC_ALL","PATH","TERM","TMPDIR"],"mode":"read-only","network":"denied","protected_write_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/.git","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/.afi","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/.agents","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/.codex","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/AGENTS.md","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur/CLAUDE.md"],"readable_paths":["/"],"readable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-bxsSur","/bin","/sbin","/usr/bin","/usr/sbin","/usr/lib","/usr/libexec","/usr/share","/System/Library","/Library/Apple","/Library/Filesystems/NetFSPlugins","/Library/Preferences","/private/etc","/private/var/db/timezone","/private/var/db/DarwinDirectory/local/recordStore.data","/private/var/select/developer_dir","/private/var/select/sh","/opt/homebrew/bin","/opt/homebrew/Cellar","/opt/homebrew/etc/gitconfig","/opt/homebrew/lib","/opt/homebrew/opt","/usr/local/bin","/Applications/Xcode.app/Contents/Developer","/Applications/Xcode.app/Contents","/Users/bart.smykla@konghq.com/.local/bin/afi"],"writable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/afi-sandbox-HXwERA"]},"schema_version":1,"source":"openrouter","sources":[{"auth":{"mode":"api_key"},"source":"openrouter","usage":{"cache_read_tokens":0,"cache_write_tokens":0,"cost_usd":0.940338,"estimated_tokens":0,"input_tokens":334869,"output_tokens":2040,"reasoning_tokens":25020,"requests":12,"total_tokens":361929}}],"system_prompt":{"file":null,"mode":"builtin"},"tools":["read_file","write_file","edit_file","list_dir","search_files","glob_files","run_bash","wait_background"],"usage":{"budget":{"converged":false,"hard_ratio":0.95,"limit_usd":8.0,"soft_ratio":0.8,"spent_usd":0.940338,"stopped":false},"cache_read_tokens":0,"cache_write_tokens":0,"cost_usd":0.940338,"estimated_tokens":0,"input_tokens":334869,"output_tokens":2040,"reasoning_tokens":25020,"refused_by_approval":0,"refused_by_policy":0,"refused_tool_calls":0,"requests":12,"total_tokens":361929}}