chore: add contributor setup task

README.md

@@ -118,17 +118,25 @@ This produces either `./exports/activity.json` or, when splitting is needed, fil
 
 ## Development setup
 
-This repository uses `mise` to install toolchain dependencies.
+This repository uses `mise` for contributor setup and toolchain management.
 
-Install the pinned tools:
+Recommended first command for contributors:
 
 ```bash
-mise install
+mise run setup
 ```
 
-Install git hooks:
+`mise run setup` keeps local setup to one command by:
+
+- installing the pinned tools with `mise install`
+- running `go mod tidy` to sync Go module dependencies
+- installing the local git hooks with `lefthook install`
+
+If you need to run the steps manually:
 
 ```bash
+mise install
+go mod tidy
 lefthook install
 ```
 

mise.toml

@@ -9,3 +9,11 @@ pnpm = "10.28.1"
 python = "3"
 rust = "latest"
 uv = "latest"
+
+[tasks.setup]
+description = "Install tools, tidy Go modules, and install git hooks"
+run = """
+mise install
+go mod tidy
+lefthook install
+"""