Bump version to 1.1.6; fix storage bugs, tests, CI pipeline and Docker config

Storage fixes:
- Fix bloom filter hash2 OverflowDefect (uint64 instead of int Hash)
- Fix MemTable.put size calculation on overwrite (was leaking size)
- Fix fuzz_test duplicate-key issues in LSM delete and SSTable tests

Test fixes:
- Fix stress_test.nim: replace deprecated threadpool with std/threads
- Fix fuzz_test.nim: add missing imports (tables, algorithm, sets)
- Fix fuzz_test.nim: var sst for close() compatibility
- Remove unused imports from test_all.nim and bench_all.nim

Docker / CI fixes:
- Fix Dockerfile.source: invalid nimlang/nim:2.2.10-alpine tag → 2.2.10 + ubuntu:24.04 runtime
- Fix Dockerfile.source healthcheck (--spider → -qO- for 200 OK)
- Fix Dockerfile run comment ports (9470/9471 → 9912/9913)
- Fix scripts/docker-run.sh healthcheck port (9470 → 9912)
- Add ARG BUILD_DATE/VCS_REF to Dockerfile for docker-build.sh
- Update all version strings 1.1.4 → 1.1.6 across nimble/docker/source/docs

docs/bg/installation.md

@@ -143,7 +143,7 @@ strip build/baradadb
 
 ```bash
 ./build/baradadb --version
-# Очакван резултат: BaraDB v1.1.4 — Multimodal Database Engine
+# Очакван резултат: BaraDB v1.1.6 — Multimodal Database Engine
 ```
 
 ## Стартиране на Тестове
@@ -234,7 +234,7 @@ docker-compose up -d
 Добавете към вашия `.nimble` файл:
 
 ```nim
-requires "barabadb >= 1.1.4"
+requires "barabadb >= 1.1.6"
 ```
 
 Използване в кода:
@@ -255,7 +255,7 @@ db.close()
 ./build/baradadb
 
 # Очакван изход:
-# BaraDB v1.1.4 — Multimodal Database Engine
+# BaraDB v1.1.6 — Multimodal Database Engine
 # BaraDB TCP listening on 127.0.0.1:9472
 
 # Тестване с HTTP API