chore(lint): simplify golangci-lint configuration

Reduce enabled linters to misspell with standard defaults, add gofmt formatter,
move errcheck settings, and minimize run and issues configurations for brevity.

.golangci.yml

@@ -1,107 +1,14 @@
 version: "2"
-
-run:
-  timeout: 5m
-  tests: true
-  concurrency: 4
-
 linters:
-  disable-all: true
+  default: standard
   enable:
-    - bodyclose
-    - copyloopvar
-    - errcheck
-    - errorlint
-    - govet
-    - ineffassign
-    - intrange
     - misspell
-    - nilnil
+  settings:
-    - prealloc
-    - sloglint
-    - staticcheck
-    - tparallel
-    - unconvert
-    - unparam
-    - unused
-    - usestdlibvars
-
-formatters:
-  enable:
-    - gofmt
-
-linters-settings:
     errcheck:
       check-type-assertions: true
       check-blank: false
-  govet:
+formatters:
-    enable-all: true
+  enable:
-    disable:
+    - gofmt
-      - fieldalignment # Often too pedantic for small projects
+run:
-  revive:
+  timeout: 5m
-    # Use default rules and a few extra ones
-    rules:
-      - name: blank-imports
-      - name: context-as-first-argument
-      - name: context-keys-type
-      - name: dot-imports
-      - name: error-return
-      - name: error-strings
-      - name: error-naming
-      - name: if-return
-      - name: increment-decrement
-      - name: var-naming
-      - name: var-declaration
-      - name: range
-      - name: receiver-naming
-      - name: time-naming
-      - name: unexported-return
-      - name: indent-error-flow
-      - name: errorf
-      - name: empty-block
-      - name: superfluous-else
-      - name: unreachable-code
-      - name: redefinition
-      - name: unused-parameter
-        arguments:
-          - allowParamNames: "^_"
-      - name: exported
-        disabled: true
-      - name: package-comments
-        disabled: true
-  gocritic:
-    enabled-tags:
-      - diagnostic
-      - experimental
-      - opinionated
-      - performance
-      - style
-    disabled-checks:
-      - hugeParam # Can be noisy
-      - rangeValCopy # Can be noisy
-      - exitAfterDefer # Common in simple CLI tools
-  gosec:
-    excludes:
-      - G204 # Subprocess launched with variable (needed for git commands)
-      - G304 # File inclusion via variable (common in CLI tools)
-      - G306 # Perms 0644 are fine for CLI output
-      - G115 # Int overflow on int64 to int conversion
-
-issues:
-  exclude-use-default: false
-  max-issues-per-linter: 0
-  max-same-issues: 0
-  exclude: []
-  exclude-rules:
-    - linters:
-        - gosec
-      text: "G304"
-    - linters:
-        - gocritic
-      text: "exitAfterDefer"
-    - path: _test\.go
-      linters:
-        - gosec
-        - unparam
-        - errcheck
-      text: "dc.UpdateStatus|dc.Submit"