Revert "update gitignore to ignore development guide" (#635)

* Revert "update gitignore to ignore development guide (#634)"

This reverts commit 1ed3b00.

* add the ai guide

Author: lodewiges

.gitignore

@@ -32,6 +32,3 @@
 
 # Ignore activestorage files
 /storage
-
-# Ignore development guide
-AI_DEVELOPMENT_GUIDE.md

AI_DEVELOPMENT_GUIDE.md

@@ -0,0 +1,110 @@
+# AI Dev Guide - AMBER API
+
+## Env
+Container: `development-environment-alpha-1`
+Path in container: `~/amber-api`
+Shell: Must use `/bin/bash -l` for PATH
+CMD: `docker exec -it development-environment-alpha-1 /bin/bash -l -c "cd ~/amber-api && bundle exec <cmd>"`
+Direct: Enter container, `cd ~/amber-api`, then run `bundle exec <cmd>`
+
+## Rules
+1. Follow existing patterns
+2. Tests for everything (95%+ coverage)
+3. Follow RuboCop or document exception with reason
+4. Keep it simple: convention over configuration
+5. Don't add gems unless they have real benefit (student-maintained, avoid bloat)
+
+## RuboCop
+Config: `.rubocop.yml`
+Target: Rails 7.2, Ruby 3.3, NewCops: enable
+Disabled: HttpPositionalArguments, HasManyOrHasOneDependent, InverseOf, LexicallyScopedActionFilter, RSpec/LeadingSubject, Documentation, FrozenStringLiteralComment, GuardClause
+Modified: RSpec/NestedGroups Max:5, Style/ClassAndModuleChildren excludes v1 resources, Metrics/BlockLength excludes spec/**
+Exceptions: Must explain why in .rubocop.yml comments
+
+## Structure
+Resources: `app/resources/v1/*.rb` extends `V1::ApplicationResource < JSONAPI::Resource`
+Tests: `spec/resources/v1/*_spec.rb` type: :resource
+Factories: `spec/factories/*.rb` use FactoryBot + Faker
+
+## Resource Template
+```ruby
+# app/resources/v1/model_resource.rb
+class V1::ModelResource < V1::ApplicationResource
+  attributes :attr1, :attr2
+  has_one :user
+  has_many :items
+  filter :field
+  
+  def self.creatable_fields(context)
+    %i[attr1 attr2]
+  end
+  
+  def self.updatable_fields(context)
+    creatable_fields(context)
+  end
+  
+  def self.searchable_fields
+    %i[attr1 attr2]
+  end
+end
+```
+
+## Test Template
+```ruby
+# spec/resources/v1/model_resource_spec.rb
+require 'rails_helper'
+
+RSpec.describe V1::ModelResource, type: :resource do
+  let(:user) { create(:user) }
+  let(:context) { { user: } }
+
+  describe '#creatable_fields' do
+    it { expect(described_class.creatable_fields(context)).to match_array(%i[attr1 attr2]) }
+  end
+
+  describe '#updatable_fields' do
+    it { expect(described_class.updatable_fields(context)).to match_array(%i[attr1 attr2]) }
+  end
+end
+```
+
+## Factory Template
+```ruby
+# spec/factories/models.rb
+FactoryBot.define do
+  factory :model do
+    user
+    attr1 { Faker::Lorem.word }
+    attr2 { [true, false].sample }
+  end
+end
+```
+
+## Test What
+Resources: creatable_fields, updatable_fields, fetchable_fields, searchable_fields, filters, relationships, attributes, permissions
+Models: validations, associations, scopes, methods, callbacks
+Controllers: auth, Pundit policies, response codes, response body, error handling
+
+## Commands
+Test all: `bundle exec rspec`
+Test file: `bundle exec rspec spec/path/to/file_spec.rb`
+Test line: `bundle exec rspec spec/path/to/file_spec.rb:12`
+RuboCop: `bundle exec rubocop`
+RuboCop fix: `bundle exec rubocop -a`
+Guard: `bundle exec guard`
+DB: `bundle exec rails db:migrate`, `bundle exec rails g migration Name`
+
+## Docker Commands
+Enter: `docker exec -it development-environment-alpha-1 /bin/bash -l` then `cd ~/amber-api`
+Start: `cd "C:/Users/jorai/Programeren/1. Alpha/1. Development/amber-api" && docker-compose -f docker-compose.development.yml up -d api`
+Stop: `docker-compose -f docker-compose.development.yml down`
+Logs: `docker logs development-environment-alpha-1`
+
+## Pitfalls
+- Don't use `docker exec ... bundle exec ...` directly (PATH + working dir issues)
+- Don't skip tests
+- Don't ignore RuboCop
+- Don't use hash rockets `{:key => val}` except in excluded dirs
+- Don't over-engineer
+- Don't use `_context` param if unused (keep it for consistency)
+- Do use existing patterns from ApplicationResource for permissions