feat(l1): persist state-history journal at block commit

Adds a per-block reverse-diff journal in a new STATE_HISTORY column family.
Each non-batch trie commit captures pre-images for every overwritten trie
node and flat-KV entry, then stages a JournalEntry in the same write batch
as the trie writes (atomic on commit). Finality pruning issues a single
delete_range when finalized advances.

No reorg consumer yet; this PR is the audit-trail foundation for the
deep-reorg work in #6685. Skipped entirely during full sync (batch_mode).

Author: edg-l

crates/storage/api/mod.rs

@@ -88,6 +88,22 @@ pub trait StorageWriteBatch: Send {
     /// Removes a key-value pair from the specified table.
     fn delete(&mut self, table: &'static str, key: &[u8]) -> Result<(), StoreError>;
 
+    /// Removes every key in `[start, end)` from the specified table.
+    ///
+    /// Half-open range; `end` is exclusive. Equivalent to enumerating each key
+    /// in the range and calling [`delete`], but backends with native range-delete
+    /// support (e.g. RocksDB's `delete_range_cf`) can implement it more efficiently.
+    ///
+    /// Lexicographic byte order is used for the range bounds — callers using
+    /// numeric keys must encode them in a representation whose lex order matches
+    /// numeric order (e.g. `u64::to_be_bytes()`).
+    fn delete_range(
+        &mut self,
+        table: &'static str,
+        start: &[u8],
+        end: &[u8],
+    ) -> Result<(), StoreError>;
+
     /// Commits all changes made in this transaction.
     fn commit(&mut self) -> Result<(), StoreError>;
 }

crates/storage/api/tables.rs

@@ -92,6 +92,14 @@ pub const STORAGE_FLATKEYVALUE: &str = "storage_flatkeyvalue";
 
 pub const MISC_VALUES: &str = "misc_values";
 
+/// State-history journal column family: [`u8; 8`] => [`Vec<u8>`]
+/// - [`u8; 8`] = `block_number.to_be_bytes()` (big-endian so lex order == numeric order)
+/// - [`Vec<u8>`] = `JournalEntry::encode()`
+///
+/// Stores one reverse-diff entry per committed block, enabling reorgs deeper
+/// than the in-memory `TrieLayerCache`. Pruned at finality.
+pub const STATE_HISTORY: &str = "state_history";
+
 /// Execution witnesses column family: [`Vec<u8>`] => [`Vec<u8>`]
 /// - [`Vec<u8>`] = Composite key
 ///    ```rust,no_run
@@ -107,7 +115,7 @@ pub const EXECUTION_WITNESSES: &str = "execution_witnesses";
 /// - [`Vec<u8>`] = RLP-encoded `BlockAccessList`
 pub const BLOCK_ACCESS_LISTS: &str = "block_access_lists";
 
-pub const TABLES: [&str; 20] = [
+pub const TABLES: [&str; 21] = [
     CHAIN_DATA,
     ACCOUNT_CODES,
     ACCOUNT_CODE_METADATA,
@@ -128,4 +136,5 @@ pub const TABLES: [&str; 20] = [
     MISC_VALUES,
     EXECUTION_WITNESSES,
     BLOCK_ACCESS_LISTS,
+    STATE_HISTORY,
 ];

crates/storage/backend/in_memory.rs

@@ -181,8 +181,31 @@ impl StorageWriteBatch for InMemoryWriteTx {
         Ok(())
     }
 
+    fn delete_range(
+        &mut self,
+        table: &'static str,
+        start: &[u8],
+        end: &[u8],
+    ) -> Result<(), StoreError> {
+        let mut db = self
+            .backend
+            .write()
+            .map_err(|_| StoreError::Custom("Failed to acquire write lock".to_string()))?;
+
+        let db_mut = Arc::make_mut(&mut *db);
+        if let Some(table_ref) = db_mut.get_mut(table) {
+            table_ref.retain(|k, _| !(k.as_slice() >= start && k.as_slice() < end));
+        }
+        Ok(())
+    }
+
     fn commit(&mut self) -> Result<(), StoreError> {
-        // FIXME: in-memory writes aren't atomic
+        // FIXME: in-memory writes aren't atomic. Every `put`, `delete`, and
+        // `delete_range` above mutates the live `Arc<Database>` immediately under
+        // the write lock; `commit` is a no-op. Anyone using this backend cannot
+        // rely on multi-op atomicity (e.g. the journal entry + trie writes in
+        // `apply_trie_updates`, or the `delete_range` + finalized-number update
+        // in `forkchoice_update_inner`).
         Ok(())
     }
 }

crates/storage/backend/rocksdb.rs

@@ -365,6 +365,20 @@ impl StorageWriteBatch for RocksDBWriteTx {
         Ok(())
     }
 
+    fn delete_range(
+        &mut self,
+        table: &'static str,
+        start: &[u8],
+        end: &[u8],
+    ) -> Result<(), StoreError> {
+        let cf = self
+            .db
+            .cf_handle(table)
+            .ok_or_else(|| StoreError::Custom(format!("Table {table:?} not found")))?;
+        self.batch.delete_range_cf(&cf, start, end);
+        Ok(())
+    }
+
     fn commit(&mut self) -> Result<(), StoreError> {
         // Take ownership of the batch (replaces it with an empty one) since db.write() consumes it
         let batch = std::mem::take(&mut self.batch);