feat(dev): add air live-reload with make watch

.air.toml

@@ -0,0 +1,18 @@
+root = "."
+tmp_dir = "tmp"
+
+[build]
+  bin = "./tmp/nib"
+  cmd = "go build -o ./tmp/nib ."
+  args_bin = ["serve"]
+  delay = 500
+  exclude_dir = ["tmp", "testdata", "docs"]
+  exclude_regex = ["_test\\.go$"]
+  include_ext = ["go", "html", "css", "js", "svg"]
+  kill_delay = 500
+
+[log]
+  time = false
+
+[misc]
+  clean_on_exit = true

.gitignore

@@ -1,5 +1,6 @@
 # Binary
 nib
+tmp/
 
 # Database
 *.db

Makefile

@@ -2,7 +2,7 @@ BINARY  := nib
 MODULE  := github.com/lerko/nib
 GOFLAGS := -trimpath
 
-.PHONY: build dev test lint fmt vet clean run help
+.PHONY: build dev watch test lint fmt vet clean run help
 
 ## —— Build ——————————————————————————————————
 
@@ -12,6 +12,9 @@ build: ## Build production binary
 dev: ## Build and run with default serve
 	go run . serve
 
+watch: ## Live-reload dev server (requires air)
+	air
+
 ## —— Quality ————————————————————————————————
 
 test: ## Run all tests