fix(rpc): self-describe reads chain name from genesis

crates/sentrix-core/src/blockchain.rs

@@ -458,6 +458,14 @@ pub struct Blockchain {
     pub mempool_sender_count: std::collections::HashMap<String, u32>,
     pub total_minted: u64,
     pub chain_id: u64, // kept pub — read-only constant used by external clients
+    /// Display name of this network (eg "Sentrix Chain", "Sentrix Testnet").
+    /// Sourced from the loaded genesis `[chain].name` so testnet binaries
+    /// don't lie about being mainnet on the `/` self-describe endpoint.
+    /// Default exists only because pre-genesis ctors (tests) skip the
+    /// genesis path; real boot always overwrites this in
+    /// `new_with_genesis`.
+    #[serde(default = "Blockchain::default_chain_name")]
+    pub chain_name: String,
     /// Binary Sparse Merkle Tree for account state.
     /// None until init_trie() is called; not persisted in MDBX state blob.
     #[serde(skip)]
@@ -624,6 +632,13 @@ fn default_block_source() -> crate::block_executor::BlockSource {
 }
 
 impl Blockchain {
+    /// Default for the `chain_name` serde-skip field — only matters for
+    /// pre-genesis state-blob deserialisations that predate the field.
+    /// Real boot always overwrites via `new_with_genesis`.
+    fn default_chain_name() -> String {
+        "Sentrix Chain".to_string()
+    }
+
     /// Construct a blockchain initialised from the embedded canonical mainnet
     /// genesis. Thin wrapper over [`Blockchain::new_with_genesis`].
     ///
@@ -658,6 +673,7 @@ impl Blockchain {
                 .ok()
                 .and_then(|v| v.parse().ok())
                 .unwrap_or(genesis.chain.chain_id),
+            chain_name: genesis.chain.name.clone(),
             state_trie: None,
             mdbx_storage: None,
             stake_registry: sentrix_staking::staking::StakeRegistry::new(),

crates/sentrix-core/src/storage.rs

@@ -57,6 +57,29 @@ impl Storage {
             }
         };
 
+        // Upgrade-path fix-up for chain_name. The field gets a serde
+        // default of "Sentrix Chain" so old state blobs deserialise
+        // cleanly, but on testnet that means the loaded value silently
+        // takes mainnet's name. Override from the canonical chain_id
+        // mapping so the self-describe endpoint reflects the network
+        // this binary is actually running. The very first save_blockchain
+        // after this fix-up persists the corrected name so subsequent
+        // boots find it already right.
+        let canonical = match bc.chain_id {
+            7119 => Some("Sentrix Chain"),
+            7120 => Some("Sentrix Testnet"),
+            _ => None,
+        };
+        if let Some(name) = canonical
+            && bc.chain_name != name
+        {
+            tracing::info!(
+                "chain_name fix-up on load: chain_id={} blob={:?} → {:?}",
+                bc.chain_id, bc.chain_name, name,
+            );
+            bc.chain_name = name.to_string();
+        }
+
         // Load only the sliding window (last CHAIN_WINDOW_SIZE blocks) into RAM.
         let height = self
             .chain

crates/sentrix-rpc/src/routes/ops.rs

@@ -29,10 +29,16 @@ pub(super) async fn root(State(state): State<SharedState>) -> Json<serde_json::V
     // explorers, wallets) need accurate consensus mode.
     let bc = state.read().await;
     let chain_id = bc.chain_id;
+    // Read the loaded genesis name so testnet binaries return
+    // "Sentrix Testnet" instead of pretending to be mainnet. Pre-fix
+    // the literal "Sentrix" string here was the same on every network
+    // — wallets that probe `/` for self-describe couldn't tell which
+    // rail they were on without checking chain_id.
+    let chain_name = bc.chain_name.clone();
     let consensus = if bc.voyager_activated { "DPoS+BFT" } else { "PoA" };
     drop(bc);
     Json(serde_json::json!({
-        "name": "Sentrix",
+        "name": chain_name,
         "version": env!("CARGO_PKG_VERSION"),
         "chain_id": chain_id,
         "consensus": consensus,