refactor: revert o use a single go module again

I experimented with multiple Go modules, but the fact is that Go is smart
enough to strip out the uneeded modules from the user's `go.mod`, so this
is not in fact needed. Also, maintaining a single module is much easier.

Author: andreynering

.github/workflows/ai.yml

@@ -0,0 +1,11 @@
+name: build
+on: [push, pull_request]
+
+jobs:
+  build:
+    uses: charmbracelet/meta/.github/workflows/build.yml@main
+    with:
+      go-version: ""
+      go-version-file: ./go.mod
+    secrets:
+      gh_pat: "${{ secrets.PERSONAL_ACCESS_TOKEN }}"

.github/workflows/anthropic.yml

@@ -0,0 +1,11 @@
+name: lint
+on:
+  push:
+  pull_request:
+
+jobs:
+  lint:
+    uses: charmbracelet/meta/.github/workflows/lint.yml@main
+    with:
+      golangci_path: .golangci.yml
+      timeout: 10m

.github/workflows/build.yml

@@ -1,36 +1,22 @@
 version: '3'
 
-env:
-  GOPRIVATE: github.com/charmbracelet/*
-
-vars:
-  PACKAGES:
-    - ./ai
-    - ./anthropic
-    - ./examples
-    - ./openai
-
 tasks:
   fmt:
     desc: Run gofumpt for all packages
     cmds:
-      - for: { var: PACKAGES }
-        cmd: cd {{.ITEM}} && gofmt -s -w .
+      - gofmt -s -w .
 
   modernize:
     desc: Run modernize for all packages
     cmds:
-      - for: { var: PACKAGES }
-        cmd: cd {{.ITEM}} && modernize -fix ./...
+      - modernize -fix ./...
 
   lint:
     desc: Run base linters for all packages
     cmds:
-      - for: { var: PACKAGES }
-        cmd: cd {{.ITEM}} && golangci-lint run
+      - golangci-lint run
 
   test:
     desc: Run tests for all packages
     cmds:
-      - for: { var: PACKAGES }
-        cmd: cd {{.ITEM}} && go test ./... {{.CLI_ARGS}}
+      - go test ./... {{.CLI_ARGS}}