feat(modules/claude-code): make the module ready for Coder Tasks (#160)

Related to coder/internal#700

This PR:

- makes AgentAPI a required dependency of the module. It's now used:
- to improve task reporting (by exporting `CODER_MCP_AI_AGENTAPI_URL`
before running `coder exp mcp configure claude-code`)
- to add a web chat interface to Claude (using the `Claude Code Web`
workspace app)
- removes support for tmux and screen since we don't need them if we
have AgentAPI
- makes the Claude Code CLI workspace app optional and disabled by
default - a new `experiment_cli_app` module variable controls its
presence
- makes the module spawn the `coder_ai_task` resource, which makes the
module compatible with the new Coder Tasks feature
- makes Claude Code remember the conversation between workspace restarts
using the `--continue` flag. Previously the module's implementation was
a bit bugged

Note: the filebrowser tests stopped passing because of an upstream
update in the filebrowser project around required password length. I
confirmed they are not related to this PR's changes.

---------

Co-authored-by: Ben Potter <me@bpmct.net>

Author: hugodutka

registry/coder/modules/claude-code/README.md

@@ -14,7 +14,7 @@ Run the [Claude Code](https://docs.anthropic.com/en/docs/agents-and-tools/claude
 ```tf
 module "claude-code" {
   source              = "registry.coder.com/coder/claude-code/coder"
-  version             = "1.4.0"
+  version             = "2.0.0"
   agent_id            = coder_agent.example.id
   folder              = "/home/coder"
   install_claude_code = true
@@ -30,7 +30,6 @@ module "claude-code" {
 ## Prerequisites
 
 - Node.js and npm must be installed in your workspace to install Claude Code
-- Either `screen` or `tmux` must be installed in your workspace to run Claude Code in the background
 - You must add the [Coder Login](https://registry.coder.com/modules/coder-login) module to your template
 
 The `codercom/oss-dogfood:latest` container image can be used for testing on container-based workspaces.
@@ -48,8 +47,6 @@ The `codercom/oss-dogfood:latest` container image can be used for testing on con
 > Join our [Discord channel](https://discord.gg/coder) or
 > [contact us](https://coder.com/contact) to get help or share feedback.
 
-Your workspace must have either `screen` or `tmux` installed to use this.
-
 ```tf
 variable "anthropic_api_key" {
   type        = string
@@ -88,49 +85,25 @@ resource "coder_agent" "main" {
 module "claude-code" {
   count               = data.coder_workspace.me.start_count
   source              = "registry.coder.com/coder/claude-code/coder"
-  version             = "1.4.0"
+  version             = "2.0.0"
   agent_id            = coder_agent.example.id
   folder              = "/home/coder"
   install_claude_code = true
   claude_code_version = "0.2.57"
 
   # Enable experimental features
-  experiment_use_screen   = true # Or use experiment_use_tmux = true to use tmux instead
   experiment_report_tasks = true
 }
 ```
 
-## Session Persistence (Experimental)
-
-Enable automatic session persistence to maintain Claude Code sessions across workspace restarts:
-
-```tf
-module "claude-code" {
-  count               = data.coder_workspace.me.start_count
-  source              = "registry.coder.com/coder/claude-code/coder"
-  version             = "1.4.0"
-  agent_id            = coder_agent.example.id
-  folder              = "/home/coder"
-  install_claude_code = true
-
-  # Enable tmux with session persistence
-  experiment_use_tmux                   = true
-  experiment_tmux_session_persistence   = true
-  experiment_tmux_session_save_interval = "10" # Save every 10 minutes
-  experiment_report_tasks               = true
-}
-```
-
-Session persistence automatically saves and restores your Claude Code environment, including working directory and command history.
-
 ## Run standalone
 
-Run Claude Code as a standalone app in your workspace. This will install Claude Code and run it directly without using screen or any task reporting to the Coder UI.
+Run Claude Code as a standalone app in your workspace. This will install Claude Code and run it without any task reporting to the Coder UI.
 
 ```tf
 module "claude-code" {
   source              = "registry.coder.com/coder/claude-code/coder"
-  version             = "1.4.0"
+  version             = "2.0.0"
   agent_id            = coder_agent.example.id
   folder              = "/home/coder"
   install_claude_code = true