Track CAS providers

docs/architecture.md

@@ -130,9 +130,11 @@ imported signed peer card over the daemon-owned Iroh control ALPN. The serving
 daemon validates the caller's peer-card signature and observed Iroh EndpointID,
 then reduces local auth ops and requires `cas.fetch` on `resource:cas:local`
 before returning blob bytes. The requester verifies that the returned bytes hash
-to the requested BLAKE3 CAS hash before storing them. Iroh-blobs, provider
-tracking, encrypted blobs, richer cache policies, cross-node file roots, and
-automatic conflict detection are future work.
+to the requested BLAKE3 CAS hash before storing them. Successful fetches update
+durable local provider metadata keyed by CAS hash and peer node, which can be
+inspected through `geth cas providers <hash>`. Iroh-blobs, encrypted blobs,
+richer cache policies, cross-node file roots, and automatic conflict detection
+are future work.
 
 `geth-db` currently registers local SQLite paths as DB resources and reports
 local-only sync status plus a read-only SQLite schema summary/hash. It also

docs/roadmap.md

@@ -248,9 +248,12 @@ authorization and durable-state boundaries clear.
   - `[x]` The requester verifies returned bytes against the requested BLAKE3
     CAS hash before storing them locally.
   - `[x]` Local add/get/hash/has/list behavior remains backward compatible.
+  - `[x]` Successful fetches record the serving peer as a local provider for
+    the CAS hash.
+  - `[x]` `geth cas providers <hash>` lists locally known providers.
+  - `[x]` Tests cover local provider metadata storage.
   - `[ ]` Replace the bootstrap control-ALPN transfer with `iroh-blobs`
     provider/fetch behavior.
-  - `[ ]` Provider tracking is recorded locally.
 
 - `[x]` CAS pin and cache policy.
   Acceptance criteria: