v1.1.7: deep security & reliability audit — 33 bugs fixed

Critical (5):
- Reject empty JWT secret when authEnabled (server.nim)
- Fix 2PC marking uncontacted participants as prepared/committed (disttxn.nim)
- Fix Raft commit index calculation for even-sized clusters (raft.nim)
- Fix REP/DISTTXN protocol auth bypass (server.nim)
- Fix HTTP backup/restore path traversal (httpserver.nim)

High (11):
- Fix WAL write race with flush (lsm.nim)
- Fix MVCC savepoint/rollback deep-copy writeSet (mvcc.nim)
- Fix table mutation during deadlock iteration (mvcc.nim)
- Fix LIMIT 0 returning all rows (executor.nim)
- Fix COUNT(col) counting NULL values — 3 locations (executor.nim)
- Fix EXISTS subquery lowering missing subqueryPlan (executor.nim)
- Fix Raft appendEntries/applyCommitted array vs logical index (raft.nim)
- Fix timing attacks on constantTimeCompare and SCRAM (auth.nim, scram.nim)
- Fix B-tree leaf merge phantom separator key (btree.nim)
- Fix SSL verifyPeer not applied to newContext (ssl.nim)
- Fix sharding connectWithTimeout missing SO_ERROR check (sharding.nim)
- Fix sync replication returning success on partial ack (replication.nim)
- Fix WebSocket JWT expiration not validated (websocket.nim)

Medium (13):
- Fix writeSSTable partial file → tmp + atomic rename (lsm.nim)
- Fix multi-CTE table loss (executor.nim)
- Fix nl_to_sql DML restricted to superuser (executor.nim)
- Fix unbounded plan cache — max 10000 (adaptive.nim)
- Fix migration lock crash persistence — timestamp + stale detection (executor.nim)
- Fix admin panel auth (httpserver.nim)
- Fix MVCC unbounded txn tracking — prune in compactVersions (mvcc.nim)
- Fix connection pool maxLifetime check (pool.nim)
- Fix JWT JSON parser backslash escapes (auth.nim)
- Fix substr(s, start) returning single char (udf.nim)
- Fix loadSSTable minimum file-size check (lsm.nim)
- Fix compaction mmap leak (compaction.nim)
- Fix JSON injection in hybrid_search_filtered (executor.nim)

Low (4):
- Raft loadState logs error instead of silent discard
- Replication healthCheck double-close fixed
- Lexer readIdent double column counting fixed
- WebSocket frame 32-bit overflow guard

All 448 tests passing, 0 failures. Bump version to 1.1.7.

README.md

@@ -4,7 +4,7 @@
 
 **A multimodal database engine written in Nim — 100% native, zero dependencies.**
 
-[![Version](https://img.shields.io/badge/version-1.1.6-blue.svg)](baradadb.nimble)
+[![Version](https://img.shields.io/badge/version-1.1.7-blue.svg)](baradadb.nimble)
 [![Documentation](https://img.shields.io/badge/docs-2_languages-blue.svg)](docs/index.md)
 [![Stars](https://img.shields.io/github/stars/katehonz/barabaDB?style=social)](https://github.com/katehonz/barabaDB)
 
@@ -1438,7 +1438,7 @@ src/barabadb/
 ## Tests
 
 ```bash
-# Run all tests (340+ tests, 60+ suites)
+# Run all tests (448 tests, 60+ suites)
 nim c --path:src -r tests/test_all.nim
 
 # Run benchmarks
@@ -1489,6 +1489,10 @@ features are still being refined:
 All core functionality is complete and production-tested. The roadmap above
 reflects 100% completion across all major phases.
 
+## Changelog
+
+See [CHANGELOG.md](CHANGELOG.md) for full release history. The latest release (**v1.1.7**) includes 33 bug fixes across security, data integrity, query correctness, and resource management.
+
 ## License
 
 BSD 3-Clause License