Add local CAS file roots

docs/architecture.md

@@ -92,8 +92,11 @@ storage. Local pin/unpin metadata is tracked in SQLite and surfaced in
 `cas list`. `cas cleanup` removes unpinned local blobs while retaining pinned
 blobs. The CAS crate can build deterministic tree objects that describe
 directories, files, executable bits, and file blob hashes; those tree objects
-are stored as CAS blobs. Iroh-blobs, providers, encrypted blobs, richer cache
-policies, file roots, and sync conflict handling are future work.
+are stored as CAS blobs. The daemon can register local file roots and scan them
+into CAS tree objects while reporting create/update/delete/rename changes. These
+scans are local metadata only and never overwrite the working tree. Iroh-blobs,
+providers, encrypted blobs, richer cache policies, cross-node file roots, and
+sync conflict handling 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

@@ -351,11 +351,15 @@ and future group key evolution.
   - `[x]` Tree objects are content-addressed and stored in CAS.
   - `[x]` Tests cover deterministic tree hashing.
 
-- `[ ]` File roots.
+- `[~]` File roots.
   Acceptance criteria:
-  - A file root maps a local path to a CAS tree resource.
-  - Scan detects create/update/delete/rename changes.
-  - Sync never silently overwrites local changes without a recorded decision.
+  - `[x]` A file root maps a local path to a CAS tree resource.
+  - `[x]` `geth cas root add/list/scan` persists local root metadata and latest
+    tree state.
+  - `[x]` Scan detects create/update/delete/rename changes.
+  - `[x]` Scan output documents that geth never overwrites file roots without a
+    recorded future sync decision.
+  - `[ ]` File roots can be synced across nodes.
 
 - `[ ]` Conflict handling.
   Acceptance criteria: