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

src/barabadb/core/httpserver.nim

@@ -199,7 +199,7 @@ proc queryHandler(server: HttpServer): RequestHandler =
 proc healthHandler(): RequestHandler =
   return proc(request: Request) {.gcsafe.} =
     let ctx = newContext(request)
-    ctx.json(%*{"status": "ok", "version": "1.1.4"})
+    ctx.json(%*{"status": "ok", "version": "1.1.6"})
 
 proc metricsHandler(server: HttpServer): RequestHandler =
   return proc(request: Request) {.gcsafe.} =
@@ -535,7 +535,7 @@ function showTab(idx){
 }
 setInterval(() => { if(document.querySelectorAll('.panel')[4].classList.contains('active')) loadMetrics() }, 5000)
 </script>
-<div class='status' style='text-align:center;padding:10px'>BaraDB v1.1.4 — Multimodal Database Engine</div>
+<div class='status' style='text-align:center;padding:10px'>BaraDB v1.1.6 — Multimodal Database Engine</div>
 </body></html>"""
     request.respond(200, @[("Content-Type", "text/html; charset=utf-8")], html)