Fix changelog: split 1.4.0 (released) from new 1.5.0 (unreleased)

1.4.0 was already tagged and released. The R1-R4 optimization work
(direct JSON writer, class pickle cache, PGO) belongs in 1.5.0.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jensens

CHANGES.md

@@ -1,10 +1,7 @@
 # Changelog
 
-## 1.4.0 (2026-02-25)
+## 1.5.0 (unreleased)
 
-- Add `decode_zodb_record_for_pg_json()` — converts ZODB pickle records
-  directly to a JSON string entirely in Rust with the GIL released,
-  eliminating the intermediate Python dict + `json.dumps()` step
 - Direct PickleValue → JSON string writer (`json_writer.rs`), bypassing
   all `serde_json::Value` intermediate allocations (PG path 1.3-3.3x
   faster than dict + `json.dumps()`)
@@ -15,8 +12,6 @@
   replaces 7 opcode writes for ~99.6% of records
 - O(1) `@cls` hash lookup replaces O(n) key scan for marker detection
 - Direct i64 LONG1 encoding (eliminates BigInt heap allocation)
-- Enable thin LTO (`lto = "thin"`) and single codegen unit
-  (`codegen-units = 1`) in release profile
 - Profile-guided optimization (PGO) support with real FileStorage +
   synthetic data profiling (adds 5-15%)
 
@@ -27,6 +22,16 @@
 - PG JSON path: 1.4x faster at median on 1,692 real ZODB records
 - Full codec overhead: ~28 µs per object (both directions)
 
+## 1.4.0 (2026-02-24)
+
+- Add `decode_zodb_record_for_pg_json()` — converts ZODB pickle records
+  directly to a JSON string entirely in Rust with the GIL released,
+  eliminating the intermediate Python dict + `json.dumps()` step
+  (1.3x faster full pipeline on real-world data)
+- Enable thin LTO (`lto = "thin"`) and single codegen unit
+  (`codegen-units = 1`) in Cargo release profile for 6-9% faster
+  decode/encode
+
 ## 1.3.0 (2026-02-24)
 
 - Fix SETITEMS/SETITEM/APPENDS/APPEND on dict/list subclasses (OrderedDict,

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "zodb-json-codec"
-version = "1.4.0"
+version = "1.5.0"
 edition = "2021"
 description = "Fast pickle ↔ JSON transcoder for ZODB, implemented in Rust"
 readme = "README.md"