Add Nix flake for mcproxyctl

Vendor dependencies and expose mcproxyctl binary via nix build.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vendor/github.com/oschwald/maxminddb-golang/.golangci.toml

@@ -0,0 +1,192 @@
+[run]
+# This is needed for precious, which may run multiple instances
+# in parallel
+allow-parallel-runners = true
+go = "1.21"
+tests = true
+timeout = "10m"
+
+[linters]
+enable-all = true
+disable = [
+    "cyclop",
+    "depguard",
+    "err113",
+    "execinquery",
+    "exhaustive",
+    "exhaustruct",
+    "forcetypeassert",
+    "funlen",
+    "gochecknoglobals",
+    "godox",
+    "gomnd",
+    "inamedparam",
+    "interfacebloat",
+    "mnd",
+    "nlreturn",
+    "nonamedreturns",
+    "paralleltest",
+    "thelper",
+    "testpackage",
+
+    "varnamelen",
+    "wrapcheck",
+    "wsl",
+
+    # Require Go 1.22
+    "copyloopvar",
+    "intrange",
+]
+
+[linters-settings.errorlint]
+errorf = true
+asserts = true
+comparison = true
+
+[linters-settings.exhaustive]
+default-signifies-exhaustive = true
+
+[linters-settings.forbidigo]
+# Forbid the following identifiers
+forbid = [
+    { p = "Geoip", msg = "you should use `GeoIP`" },
+    { p = "geoIP", msg = "you should use `geoip`" },
+    { p = "Maxmind", msg = "you should use `MaxMind`" },
+    { p = "^maxMind", msg = "you should use `maxmind`" },
+    { p = "Minfraud", msg = "you should use `MinFraud`" },
+    { p = "^minFraud", msg = "you should use `minfraud`" },
+    { p = "^math.Max$", msg = "you should use the max built-in instead." },
+    { p = "^math.Min$", msg = "you should use the min built-in instead." },
+    { p = "^os.IsNotExist", msg = "As per their docs, new code should use errors.Is(err, fs.ErrNotExist)." },
+    { p = "^os.IsExist", msg = "As per their docs, new code should use errors.Is(err, fs.ErrExist)" },
+]
+
+[linters-settings.gci]
+sections = ["standard", "default", "prefix(github.com/oschwald/maxminddb-golang)"]
+
+[linters-settings.gofumpt]
+extra-rules = true
+
+[linters-settings.govet]
+enable-all = true
+disable = "shadow"
+
+[linters-settings.lll]
+line-length = 120
+tab-width = 4
+
+[linters-settings.misspell]
+locale = "US"
+
+[[linters-settings.misspell.extra-words]]
+typo = "marshall"
+correction = "marshal"
+
+[[linters-settings.misspell.extra-words]]
+typo = "marshalling"
+correction = "marshaling"
+
+[[linters-settings.misspell.extra-words]]
+typo = "marshalls"
+correction = "marshals"
+
+[[linters-settings.misspell.extra-words]]
+typo = "unmarshall"
+correction = "unmarshal"
+
+[[linters-settings.misspell.extra-words]]
+typo = "unmarshalling"
+correction = "unmarshaling"
+
+[[linters-settings.misspell.extra-words]]
+typo = "unmarshalls"
+correction = "unmarshals"
+
+[linters-settings.nolintlint]
+allow-unused = false
+allow-no-explanation = ["lll", "misspell"]
+require-explanation = true
+require-specific = true
+
+[linters-settings.revive]
+enable-all-rules = true
+ignore-generated-header = true
+severity = "warning"
+
+[[linters-settings.revive.rules]]
+name = "add-constant"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "cognitive-complexity"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "confusing-naming"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "confusing-results"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "cyclomatic"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "deep-exit"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "flag-parameter"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "function-length"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "function-result-limit"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "line-length-limit"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "max-public-structs"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "nested-structs"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "unchecked-type-assertion"
+disabled = true
+
+[[linters-settings.revive.rules]]
+name = "unhandled-error"
+disabled = true
+
+[linters-settings.tagliatelle.case.rules]
+avro = "snake"
+bson = "snake"
+env = "upperSnake"
+envconfig = "upperSnake"
+json = "snake"
+mapstructure = "snake"
+xml = "snake"
+yaml = "snake"
+
+[linters-settings.unparam]
+check-exported = true
+
+
+[[issues.exclude-rules]]
+linters = [
+    "govet",
+    "revive",
+]
+path = "_test.go"
+text = "fieldalignment:"