Add Docker deployment support with compose, entrypoint and docs

- Add Dockerfile (pre-built binary) and Dockerfile.source
- Add docker-compose.yml, docker-compose.prod.yml, docker-compose.override.yml
- Add docker-entrypoint.sh with non-root user support
- Add .dockerignore and helper scripts (scripts/docker-build.sh, scripts/docker-run.sh)
- Add docs/en/docker.md with full Docker guide
- Update docs/en/deployment.md and README.md
- Fix src/barabadb/core/config.nim to read BARADB_ADDRESS, BARADB_PORT, BARADB_DATA_DIR from env
- Fix src/barabadb/core/httpserver.nim missing wire import

src/barabadb/core/config.nim

@@ -1,3 +1,6 @@
+import std/os
+import std/strutils
+
 type
   BaraConfig* = object
     address*: string
@@ -37,3 +40,16 @@ proc defaultConfig*(): BaraConfig =
 
 proc loadConfig*(): BaraConfig =
   result = defaultConfig()
+  # Docker / Environment overrides
+  let envAddress = getEnv("BARADB_ADDRESS", "")
+  if envAddress.len > 0:
+    result.address = envAddress
+  let envPort = getEnv("BARADB_PORT", "")
+  if envPort.len > 0:
+    try:
+      result.port = parseInt(envPort)
+    except ValueError:
+      discard
+  let envDataDir = getEnv("BARADB_DATA_DIR", "")
+  if envDataDir.len > 0:
+    result.dataDir = envDataDir

src/barabadb/core/httpserver.nim

@@ -15,6 +15,7 @@ import ../query/parser
 import ../query/executor
 import ../storage/lsm
 import ../core/mvcc
+import ../protocol/wire
 import ../protocol/ratelimit
 import ../core/websocket
 import jwt as jwtlib