build(dev): use air for backend live reload

.air.toml

@@ -0,0 +1,17 @@
+root = "."
+tmp_dir = "_scratch/air"
+
+[build]
+cmd = "go build -o ./_scratch/air/antholume ."
+full_bin = "./_scratch/air/antholume serve"
+delay = 1000
+include_ext = ["go", "tpl", "tmpl", "html", "css", "js", "yaml", "yml"]
+exclude_dir = ["_scratch", "build", "data", "frontend", "node_modules"]
+exclude_file = ["assets/style.css"]
+stop_on_error = true
+
+[log]
+time = true
+
+[misc]
+clean_on_exit = true

.gitignore

@@ -2,6 +2,7 @@ TODO.md
 .DS_Store
 data/
 build/
+tmp/
 .direnv/
 cover.html
 node_modules

AGENTS.md

@@ -42,7 +42,7 @@ Regenerate:
 
 ### Common commands
 - Full dev stack: `make dev` (backend on `:8585` + Vite frontend on `:5173`)
-- Backend only: `make dev_backend`
+- Backend only: `make dev_backend` (live-reloads with Air)
 - Frontend only: `make dev_frontend`
 - Direct backend run: `CONFIG_PATH=./data DATA_PATH=./data REGISTRATION_ENABLED=true go run main.go serve`
 - No-auth dev run: `CONFIG_PATH=./data DATA_PATH=./data REGISTRATION_ENABLED=true DISABLE_AUTH=true DISABLE_AUTH_USER=evan go run main.go serve`

Makefile

@@ -46,7 +46,7 @@ dev:
 	$(MAKE) -j2 dev_backend dev_frontend
 
 dev_backend:
-	$(DEV_ENV) go run main.go serve
+	$(DEV_ENV) air
 
 dev_frontend:
 	cd frontend && bun run dev

README.md

@@ -138,7 +138,7 @@ Run Development:
 make dev
 
 # Or run one side only
-make dev_backend
+make dev_backend  # live-reloads with air
 make dev_frontend
 ```
 

flake.nix

@@ -20,6 +20,7 @@
       {
         devShells.default = pkgs.mkShell {
           packages = with pkgs; [
+            air
             go
             golangci-lint
             gopls