diff --git a/Cargo.lock b/Cargo.lock
index f3cec9f..4e91de7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1847,7 +1847,6 @@ dependencies = [
  "log",
  "parking_lot",
  "rand 0.8.7",
- "regex",
  "reqwest",
  "rusqlite",
  "serde",
diff --git a/core/Cargo.toml b/core/Cargo.toml
index c667795..4526c3d 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -42,7 +42,6 @@ async-trait = "0.1"
 # tinycortex's major — which `links = "git2"` turns into a hard cargo error
 # rather than a warning.
 # `store/factories.rs` exposes a tiny health router for the embedded provider.
-axum = { version = "0.8", default-features = false, features = ["http1", "json", "tokio", "query", "ws", "macros"] }
 chrono = { version = "0.4", features = ["serde"] }
 # `tinycortex/persona.rs` resolves the user's home directory for the obsidian
 # vault default.
@@ -55,7 +54,6 @@ parking_lot = "0.12"
 rand = "0.8"
 reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls", "stream"] }
 tracing = "0.1"
-regex = "1.10"
 rusqlite = { version = "=0.40.0", features = ["bundled"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
@@ -74,6 +72,12 @@ tinymemory-api = { path = "../api", features = ["test-support"] }
 # hold this crate's own store to the same contract the adapters are held to.
 # No cycle — `tinymemory-conformance` depends on `tinymemory-api` alone.
 tinymemory-conformance = { path = "../conformance" }
+# Test-only. `store::factories`' tests stand up a throwaway HTTP server to
+# exercise the embedder's failure paths — the four `axum` references in this
+# crate are all inside `mod tests`. It was declared as a normal dependency,
+# which put a web framework in the normal graph of every build linking this
+# crate (#18 §D2).
+axum = { version = "0.8", default-features = false, features = ["http1", "json", "tokio", "query", "ws", "macros"] }
 tempfile = "3"
 tokio = { version = "1", features = ["test-util"] }
 
diff --git a/core/src/engine/sync.rs b/core/src/engine/sync.rs
index 54aa871..c72553c 100644
--- a/core/src/engine/sync.rs
+++ b/core/src/engine/sync.rs
@@ -14,7 +14,16 @@ use crate::sources::{MemorySourceEntry, SourceKind};
 use crate::store::MemoryClientRef;
 use crate::Config;
 
-pub const HOST_SYNC_STATE_NAMESPACE: &str = "composio-sync-state";
+/// The KV namespace Composio sync state is persisted under.
+///
+/// Re-exported from the engine rather than re-declared. It was a second
+/// `const` holding the same literal as
+/// `tinycortex::memory::sync::state::STATE_NAMESPACE`, so the host and the
+/// engine agreed only by coincidence of the string: change either and the two
+/// would silently read and write *different* namespaces, stranding every
+/// persisted sync cursor with no error anywhere. A duplicated literal is a
+/// drift hazard precisely when the thing it names is durable (#18 §B2).
+pub use tinycortex::memory::sync::state::STATE_NAMESPACE as HOST_SYNC_STATE_NAMESPACE;
 pub use tinycortex::memory::sync::{
     RawCoverage, RawFileRef, RealCostAccumulator, RebuildOutcome, SyncAuditEntry,
 };
diff --git a/core/src/sync/composio/providers/sync_state.rs b/core/src/sync/composio/providers/sync_state.rs
index 4e33f91..d931f25 100644
--- a/core/src/sync/composio/providers/sync_state.rs
+++ b/core/src/sync/composio/providers/sync_state.rs
@@ -17,3 +17,25 @@ pub fn extract_item_id(item: &serde_json::Value, paths: &[&str]) -> Option<Strin
             .map(str::to_owned)
     })
 }
+
+#[cfg(test)]
+mod tests {
+    /// The namespace is durable, so changing it is a data migration.
+    ///
+    /// `KV_NAMESPACE` now re-exports the engine's constant, which makes host
+    /// and engine agree by construction — they previously agreed only because
+    /// two separate `const`s happened to hold the same literal. This pins the
+    /// *value* as well: every persisted Composio sync cursor lives under this
+    /// string, so a change upstream silently strands all of them. Failing here
+    /// turns that into a deliberate decision with a migration attached rather
+    /// than a quiet loss discovered when a sync re-runs from the beginning.
+    #[test]
+    fn the_state_namespace_is_pinned() {
+        assert_eq!(
+            super::KV_NAMESPACE,
+            "composio-sync-state",
+            "the Composio sync-state KV namespace changed; every persisted \
+             cursor is stored under the old value and needs migrating"
+        );
+    }
+}