docs: add comprehensive @moduledoc to all internal modules

- Add detailed documentation for Caddy.Admin.Request (HTTP client implementation)
- Add documentation for Caddy.Admin.Api (high-level API interface)
- Add documentation for Caddy.Admin (health check GenServer)
- Add documentation for Caddy.Logger.Buffer (log buffering)
- Add documentation for Caddy.Logger.Store (log storage)
- Add documentation for Caddy.Application (OTP application)

All modules now have proper @moduledoc entries explaining their:
- Purpose and responsibility
- Key features
- Usage examples (where applicable)
- Implementation details

This completes Phase 3 of the optimization plan.

Author: GSMLG-BOT

lib/caddy/admin.ex

@@ -1,5 +1,10 @@
 defmodule Caddy.Admin do
-  @moduledoc false
+  @moduledoc """
+  GenServer that periodically checks Caddy server health.
+
+  This module runs as a background process that checks the Caddy server
+  status every 15 seconds and logs any connection issues.
+  """
   require Logger
 
   use GenServer

lib/caddy/admin/api.ex

@@ -1,5 +1,32 @@
 defmodule Caddy.Admin.Api do
-  @moduledoc false
+  @moduledoc """
+  High-level interface to the Caddy Admin API.
+
+  Provides a convenient Elixir API for interacting with Caddy's admin endpoints,
+  including configuration management, server control, and health monitoring.
+
+  ## Features
+
+  - Configuration loading and reloading
+  - Caddyfile adaptation (convert to JSON)
+  - Health checks and server information
+  - Telemetry integration for monitoring
+  - Mock support for testing via RequestBehaviour
+
+  ## Examples
+
+      # Get current configuration
+      {:ok, config} = Caddy.Admin.Api.get_config()
+
+      # Load new configuration
+      Caddy.Admin.Api.load(new_config)
+
+      # Adapt Caddyfile to JSON
+      {:ok, json_config} = Caddy.Admin.Api.adapt(caddyfile_content)
+
+      # Check server health
+      {:ok, status} = Caddy.Admin.Api.health_check()
+  """
   require Logger
 
   defp request_module, do: Application.get_env(:caddy, :request_module, Caddy.Admin.Request)

lib/caddy/admin/request.ex

@@ -1,5 +1,18 @@
 defmodule Caddy.Admin.Request do
-  @moduledoc false
+  @moduledoc """
+  Low-level HTTP client for Caddy Admin API over Unix domain sockets.
+
+  This module provides direct HTTP communication with the Caddy admin API
+  using Unix domain sockets. It implements the RequestBehaviour and handles
+  GET, POST, PUT, PATCH, and DELETE operations.
+
+  ## Implementation Details
+
+  - Uses `:gen_tcp` for Unix socket communication
+  - Parses HTTP responses with `:http_bin` packet mode
+  - Automatically decodes JSON responses
+  - Returns structured response with status, headers, and body
+  """
   @behaviour Caddy.Admin.RequestBehaviour
 
   alias Caddy.Admin.Request

lib/caddy/application.ex

@@ -1,5 +1,10 @@
 defmodule Caddy.Application do
-  @moduledoc false
+  @moduledoc """
+  OTP Application for Caddy reverse proxy management.
+
+  Starts the main Caddy supervisor tree when the application starts.
+  Note: Only starts in non-test environments (see mix.exs).
+  """
 
   use Application
 

lib/caddy/logger/buffer.ex

@@ -1,5 +1,11 @@
 defmodule Caddy.Logger.Buffer do
-  @moduledoc false
+  @moduledoc """
+  GenServer that buffers log messages before writing to storage.
+
+  Collects log output from the Caddy server process and buffers
+  messages until complete lines are received. When newlines are
+  detected, complete log lines are flushed to the Logger.Store.
+  """
 
   use GenServer
   require Logger

lib/caddy/logger/store.ex

@@ -1,5 +1,10 @@
 defmodule Caddy.Logger.Store do
-  @moduledoc false
+  @moduledoc """
+  GenServer that stores Caddy server log history.
+
+  Maintains a rolling buffer of up to 50,000 log lines from the Caddy
+  server. Provides access to recent logs via the `tail/1` function.
+  """
 
   require Logger