fix(codex): pass folder variable to agentapi module (#477)

## Description

The folder variable was not being passed from the codex module to the
agentapi module, causing agentapi to use its default value of
`/home/coder` instead of the user-specified folder path.

This resulted in permission errors when the codex module tried to create
directories in `/home/coder` when users specified a different folder
like `/home/matt/foo`.

Fix by adding `folder = var.folder` to the agentapi module invocation.

## Type of Change

- [ ] New module
- [ ] New template
- [x] Bug fix
- [ ] Feature/enhancement
- [ ] Documentation
- [ ] Other

## Module Information

Path: registry/coder-labs/modules/codex
New version: v2.1.1
Breaking change: [ ] Yes [X] No

## Testing & Validation

- [x] Tests pass (`bun test`)
- [x] Code formatted (`bun fmt`)
- [x] Changes tested locally

## Related Issues
Fixes https://github.com/coder/registry/issues/476

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: DevelopmentCats <christofer@coder.com>

registry/coder-labs/modules/codex/README.md

@@ -13,7 +13,7 @@ Run Codex CLI in your workspace to access OpenAI's models through the Codex inte
 ```tf
 module "codex" {
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "2.1.0"
+  version        = "2.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = var.openai_api_key
   folder         = "/home/coder/project"
@@ -33,7 +33,7 @@ module "codex" {
 module "codex" {
   count          = data.coder_workspace.me.start_count
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "2.1.0"
+  version        = "2.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = "..."
   folder         = "/home/coder/project"
@@ -60,7 +60,7 @@ module "coder-login" {
 
 module "codex" {
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "2.1.0"
+  version        = "2.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = "..."
   ai_prompt      = data.coder_parameter.ai_prompt.value
@@ -106,7 +106,7 @@ For custom Codex configuration, use `base_config_toml` and/or `additional_mcp_se
 ```tf
 module "codex" {
   source  = "registry.coder.com/coder-labs/codex/coder"
-  version = "2.1.0"
+  version = "2.1.1"
   # ... other variables ...
 
   # Override default configuration

registry/coder-labs/modules/codex/main.tf

@@ -131,6 +131,7 @@ module "agentapi" {
   version = "1.2.0"
 
   agent_id             = var.agent_id
+  folder               = var.folder
   web_app_slug         = local.app_slug
   web_app_order        = var.order
   web_app_group        = var.group