Add local CAS cleanup policy

docs/architecture.md

@@ -89,7 +89,8 @@ Resource kinds:
 
 `geth-cas` is implemented locally first using BLAKE3 hashes and filesystem blob
 storage. Local pin/unpin metadata is tracked in SQLite and surfaced in
-`cas list`. Iroh-blobs, providers, encrypted blobs, cache cleanup, manifests,
+`cas list`. `cas cleanup` removes unpinned local blobs while retaining pinned
+blobs. Iroh-blobs, providers, encrypted blobs, richer cache policies, manifests,
 and file sync trees are future work.
 
 `geth-kv`, `geth-db`, `geth-document`, `geth-pubsub`, `geth-pipe`, and

docs/roadmap.md

@@ -200,14 +200,14 @@ authorization and durable-state boundaries clear.
   - Provider tracking is recorded locally.
   - Local add/get/hash/has/list behavior remains backward compatible.
 
-- `[~]` CAS pin and cache policy.
+- `[x]` CAS pin and cache policy.
   Acceptance criteria:
   - `[x]` `geth cas pin <hash>` persists local pin metadata.
   - `[x]` `geth cas unpin <hash>` removes local pin metadata.
   - `[x]` `geth cas list` reports pinned versus unpinned blobs.
-  - `[ ]` Pinned blobs are retained across cache cleanup.
-  - `[ ]` Unpinned cached blobs can be evicted by policy.
-  - `[ ]` Tests cover attempted eviction of pinned data.
+  - `[x]` Pinned blobs are retained across cache cleanup.
+  - `[x]` Unpinned cached blobs can be evicted by policy.
+  - `[x]` Tests cover attempted eviction of pinned data.
 
 - `[ ]` Encrypted private blobs.
   Acceptance criteria: