feat(sql): Window Functions + MERGE statement + REST bridge plan

- Add Window Functions: ROW_NUMBER, RANK, DENSE_RANK, LEAD, LAG,
  FIRST_VALUE, LAST_VALUE, NTILE with PARTITION BY, ORDER BY,
  ROWS/RANGE frame specifications
- Add MERGE/UPSERT statement with WHEN MATCHED UPDATE and
  WHEN NOT MATCHED INSERT
- Add SQL/PGQ Property Graph long-term plan in PLAN_SQL_ADVANCED.md
- Add 7 new tests for Window Functions and MERGE
- Update baraql.md documentation

docs/en/baraql.md

@@ -517,6 +517,50 @@ LIMIT 10;
 SELECT /*+ PARALLEL(4) */ * FROM large_table;
 ```
 
+## Window Functions
+
+```sql
+-- Ranking functions
+SELECT
+  name,
+  department,
+  ROW_NUMBER() OVER (PARTITION BY department ORDER BY salary DESC) AS rn,
+  RANK() OVER (PARTITION BY department ORDER BY salary DESC) AS r,
+  DENSE_RANK() OVER (PARTITION BY department ORDER BY salary DESC) AS dr
+FROM employees;
+
+-- Value functions
+SELECT
+  name,
+  salary,
+  LAG(salary, 1, 0) OVER (ORDER BY salary) AS prev_salary,
+  LEAD(salary, 1, 0) OVER (ORDER BY salary) AS next_salary,
+  FIRST_VALUE(name) OVER (PARTITION BY department ORDER BY salary) AS cheapest,
+  LAST_VALUE(name) OVER (PARTITION BY department ORDER BY salary) AS most_expensive
+FROM employees;
+
+-- Distribution functions
+SELECT name, NTILE(4) OVER (ORDER BY salary) AS quartile FROM employees;
+```
+
+### Frame Specifications
+
+```sql
+-- ROWS frame
+SUM(salary) OVER (
+  PARTITION BY department
+  ORDER BY hire_date
+  ROWS BETWEEN 1 PRECEDING AND CURRENT ROW
+)
+
+-- RANGE frame
+SUM(salary) OVER (
+  PARTITION BY department
+  ORDER BY hire_date
+  RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+)
+```
+
 ## Supported Keywords
 
 | Category | Keywords |
@@ -536,3 +580,5 @@ SELECT /*+ PARALLEL(4) */ * FROM large_table;
 | FTS | @@ (BM25 match) |
 | Recovery | RECOVER TO TIMESTAMP |
 | Functions | count, sum, avg, min, max, stddev, variance, abs, sqrt, lower, upper, len, trim, substr, now, last_insert_id |
+| Window | OVER, PARTITION BY, ROWS, RANGE, UNBOUNDED PRECEDING, CURRENT ROW, FOLLOWING |
+| Window Functions | ROW_NUMBER, RANK, DENSE_RANK, LEAD, LAG, FIRST_VALUE, LAST_VALUE, NTILE |

docs/en/changelog.md

@@ -174,6 +174,15 @@ All notable changes to BaraDB are documented in this file.
 
 ## [Unreleased]
 
+### Added
+
+- **JavaScript Client — TCP Request Queue** — Internal `_requestQueue` + `_requestLock` for safe concurrent queries. Multiple parallel `query()` / `execute()` / `ping()` calls no longer interleave binary frames on the wire.
+
+### Fixed
+
+- **Wire Protocol — Big-Endian Float Serialization** — `FLOAT32`/`FLOAT64` and vector float values are now serialized in big-endian byte order, matching the client's `readFloatBE()` / `readDoubleBE()` and ensuring cross-platform numeric accuracy.
+- **Gossip Protocol — Async UDP Socket** — Replaced synchronous `newSocket` + blocking `recvFrom` with `newAsyncSocket` + `await recvFrom`, preventing the async event loop from freezing until a UDP packet arrives.
+
 ### Planned
 
 - Query plan caching

docs/en/clients.md

@@ -45,6 +45,18 @@ await client.commit();
 await client.close();
 ```
 
+### Concurrent Queries
+
+The JavaScript client automatically serializes concurrent requests over a single TCP connection via an internal request queue. You can safely fire multiple parallel operations — their binary frames will not interleave on the wire:
+
+```typescript
+const [users, orders, stats] = await Promise.all([
+  client.query('SELECT * FROM users'),
+  client.query('SELECT * FROM orders'),
+  client.query('SELECT count(*) FROM visits')
+]);
+```
+
 ### WebSocket Streaming
 
 ```typescript

docs/en/protocol.md

@@ -98,13 +98,13 @@ Every message starts with a 8-byte header:
 | INT16 | 0x03 | 2 | Signed 16-bit integer |
 | INT32 | 0x04 | 4 | Signed 32-bit integer |
 | INT64 | 0x05 | 8 | Signed 64-bit integer |
-| FLOAT32 | 0x06 | 4 | IEEE 754 single precision |
-| FLOAT64 | 0x07 | 8 | IEEE 754 double precision |
+| FLOAT32 | 0x06 | 4 | IEEE 754 single precision (big-endian) |
+| FLOAT64 | 0x07 | 8 | IEEE 754 double precision (big-endian) |
 | STRING | 0x08 | variable | UTF-8 string (4-byte length prefix) |
 | BYTES | 0x09 | variable | Raw bytes (4-byte length prefix) |
 | ARRAY | 0x0A | variable | Array of values |
 | OBJECT | 0x0B | variable | Key-value object |
-| VECTOR | 0x0C | variable | Float32 array (4-byte length prefix) |
+| VECTOR | 0x0C | variable | Float32 array (4-byte length prefix, big-endian floats) |
 
 ### Error Message Payload