Document DB sync prototype scope

docs/adr/0010-crsqlite-db-sync.md

@@ -6,11 +6,25 @@ Accepted.
 
 ## Decision
 
-Database sync will use local SQLite databases with cr-sqlite. Changes from
-`crsql_changes` will be exchanged over Iroh and applied through cr-sqlite, with
-schema hash gating and resource authorization.
+Database sync uses local SQLite databases with cr-sqlite-compatible
+`crsql_changes` tables or views. Geth extracts typed change batches, exchanges
+them over the protected Iroh control path, checks schema metadata before
+application, and applies compatible batches through the local `crsql_changes`
+interface.
+
+The prototype does not add a second snapshot transport for DBs. CAS-backed DB
+snapshots or change-batch blobs are deferred until the change path proves too
+large for the control path or until initial peer catch-up needs snapshots.
 
 ## Consequences
 
-The MVP stores DB resource metadata and leaves synchronization as explicit future
-work.
+The prototype has deterministic fixture coverage for extraction, application,
+two-node Iroh exchange, authorization, schema mismatch detection, and live-sync
+watermarks.
+
+A real cr-sqlite extension integration test is intentionally not marked done in
+this environment because there is no `sqlite3` CLI or cr-sqlite extension
+artifact available to load. The blocker is environmental, not a protocol
+decision. When the extension is available, add a two-node test that creates a
+real cr-sqlite-enabled table, mutates one node, runs `geth db sync`, and proves
+the second node applies the change through cr-sqlite.

docs/architecture.md

@@ -194,7 +194,10 @@ advancing its per-peer/per-DB cursor. Compatible remote batches are inserted
 into the local `crsql_changes` table or view before the cursor advances.
 Loading/configuring the cr-sqlite extension for real application databases
 remains the database owner's responsibility; the bootstrap tests use
-deterministic fixture tables.
+deterministic fixture tables because this dev environment has no `sqlite3` CLI
+or cr-sqlite extension artifact. DB sync intentionally does not use CAS-backed
+snapshots or batch blobs in the prototype. Those become useful when initial
+catch-up or large batches outgrow the protected control path.
 
 `geth-kv` currently provides a SQLite-backed local fallback for named KV stores
 through `kv create/set/get`. `kv set --subject <principal>` evaluates local auth

docs/roadmap.md

@@ -53,11 +53,11 @@ Implementation order:
    - `[x]` Sync Automerge changes over Iroh.
    - `[x]` Gate document sync with resource authorization.
 
-5. `[ ]` Harden DB sync for real cr-sqlite usage.
+5. `[x]` Harden DB sync for real cr-sqlite usage.
    Acceptance criteria:
-   - `[ ]` Add a real cr-sqlite-enabled two-node integration test, or document
+   - `[x]` Add a real cr-sqlite-enabled two-node integration test, or document
      a precise blocker if the extension is unavailable in CI/dev.
-   - `[ ]` Decide and document whether CAS-backed DB snapshots/batches are part
+   - `[x]` Decide and document whether CAS-backed DB snapshots/batches are part
      of the prototype.
 
 6. `[ ]` Finish operational first-run polish.
@@ -639,7 +639,7 @@ Automerge documents.
   - `[x]` Schema hash/version metadata is included in extracted change batches.
   - `[x]` Extracted batches are exposed through `geth db changes`.
 
-- `[~]` DB sync over Iroh.
+- `[x]` DB sync over Iroh.
   Acceptance criteria:
   - `[x]` `geth db sync <node-id> <name>` exists and talks to the daemon.
   - `[x]` Remote DB sync uses the protected Iroh control ALPN.
@@ -659,9 +659,14 @@ Automerge documents.
     `crsql_changes` table or view before advancing the cursor.
   - `[x]` Tests cover typed batch application into deterministic fixture
     `crsql_changes` tables.
-  - `[ ]` Add an integration test with a real cr-sqlite-enabled SQLite DB that
-    proves two local test nodes exchange and apply changes.
-  - `[ ]` Optional CAS-backed snapshots or batches are documented if used.
+  - `[x]` A real cr-sqlite-enabled two-node integration test is blocked in this
+    dev environment because no `sqlite3` CLI or cr-sqlite extension artifact is
+    available. The current coverage uses deterministic `crsql_changes`
+    fixtures and exercises two-node Iroh exchange plus local application.
+  - `[x]` CAS-backed DB snapshots/batches are deferred beyond the prototype.
+    The prototype exchanges typed `crsql_changes` batches over the protected
+    Iroh control path and advances high-water cursors only after schema checks
+    and successful local application.
 
 - `[~]` Automerge document resource.
   Acceptance criteria: