Add lint and vulnerability scanning workflow

Add golangci-lint v2 configuration and make targets for lint/vuln.
Integrate lint+govulncheck into CI and add tools to Nix devshell.
Also bump Go toolchain to 1.25.7 and address revive lint requirements.

---
_Generated with [`mux`](https://github.com/coder/mux) • Model: `openai:gpt-5.3-codex` • Thinking: `xhigh`_

Author: ThomasK33

.github/workflows/ci.yaml

@@ -10,6 +10,36 @@ permissions:
   contents: read
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Verify vendor is up to date
+        run: |
+          go mod tidy
+          go mod vendor
+          git diff --exit-code -- go.mod go.sum vendor/
+
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: v2.8
+          args: --timeout=5m ./...
+
+      - name: Run govulncheck
+        uses: golang/govulncheck-action@v1
+        with:
+          go-version-file: go.mod
+          go-package: ./...
+
   test:
     runs-on: ubuntu-latest
     steps:

.golangci.yml

@@ -0,0 +1,25 @@
+version: "2"
+
+run:
+  timeout: 5m
+  modules-download-mode: vendor
+
+linters:
+  enable:
+    - bodyclose
+    - errorlint
+    - gosec
+    - misspell
+    - nilerr
+    - revive
+
+formatters:
+  enable:
+    - gofumpt
+  settings:
+    gofumpt:
+      extra-rules: true
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0

Makefile

@@ -2,7 +2,7 @@ GOFLAGS ?= -mod=vendor
 VENDOR_STAMP := vendor/.modules.stamp
 MODULE_FILES := go.mod $(wildcard go.sum)
 
-.PHONY: vendor test build verify-vendor codegen
+.PHONY: vendor test build lint vuln verify-vendor codegen
 
 $(VENDOR_STAMP): $(MODULE_FILES)
 	go mod tidy
@@ -18,6 +18,14 @@ test: $(VENDOR_STAMP)
 build: $(VENDOR_STAMP)
 	GOFLAGS=$(GOFLAGS) go build ./...
 
+lint: $(VENDOR_STAMP)
+	@command -v golangci-lint >/dev/null || (echo "golangci-lint not found; use nix develop" && exit 1)
+	GOFLAGS=$(GOFLAGS) golangci-lint run ./...
+
+vuln: $(VENDOR_STAMP)
+	@command -v govulncheck >/dev/null || (echo "govulncheck not found; use nix develop" && exit 1)
+	GOFLAGS=$(GOFLAGS) govulncheck ./...
+
 verify-vendor:
 	go mod tidy
 	go mod vendor

flake.lock

@@ -25,6 +25,8 @@
               goreleaser
               actionlint
               zizmor
+              golangci-lint
+              govulncheck
             ];
           };
         }

flake.nix

@@ -1,6 +1,6 @@
 module github.com/coder/coder-k8s
 
-go 1.25.6
+go 1.25.7
 
 require (
 	k8s.io/apimachinery v0.35.0

go.mod

@@ -5,8 +5,8 @@
 package deps
 
 import (
-	_ "k8s.io/apimachinery/pkg/runtime"
-	_ "k8s.io/client-go/kubernetes"
-	_ "k8s.io/code-generator"
-	_ "sigs.k8s.io/controller-runtime/pkg/client"
+	_ "k8s.io/apimachinery/pkg/runtime"           // Keep apimachinery runtime dependency vendored.
+	_ "k8s.io/client-go/kubernetes"               // Keep client-go kubernetes client vendored.
+	_ "k8s.io/code-generator"                     // Keep code-generator scripts vendored.
+	_ "sigs.k8s.io/controller-runtime/pkg/client" // Keep controller-runtime client vendored.
 )

internal/deps/deps.go

@@ -1,3 +1,4 @@
+// Package main provides the entrypoint for the coder-k8s binary.
 package main
 
 import (