PARTIAL Restructure into a single-package project

Still needed:

- full audit for references to directories named "shared" and "packages"
- verification that Xcode build still functions as expected
- verification that the `npm pack` command still produces a valid
  package

Author: jugglinmike

.gitattributes

@@ -1,79 +1,38 @@
-# ARIA-AT Automation Driver
+# macOS AT Driver Server
 
-A [WebSocket](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)
-server which allows clients to observe the text enunciated by a screen reader
-and to simulate user input
+An implementation of the [AT Driver](https://w3c.github.io/at-driver/) remote
+end designed to work with screen readers on macOS.
 
 **[aria-at-automation](https://github.com/w3c/aria-at-automation)** · [aria-at-automation-harness](https://github.com/w3c/aria-at-automation-harness) · aria-at-automation-driver · [aria-at-automation-results-viewer](https://github.com/w3c/aria-at-automation-results-viewer)
 
 ## Requirements
 
-- Microsoft Windows
-- [Node.js](https://nodejs.org), including "Tools for Native Modules" as
-  offered by the Node.js installer
-- [the Microsoft Visual C++
-  runtime](https://aka.ms/vs/16/release/vc_redist.x86.exe)
-
-<details>
-  <summary>note for project maintainers</summary>
-
-"Tools for Native Modules" is required to install the "robotjs" npm module,
-which is a dependency of this project.
-
-[The Visual C++ runtime includes
-`VCRUNTIME140.dll`](https://answers.microsoft.com/en-us/windows/forum/all/vcruntime140dll/fc4c0470-4db0-4e7b-9537-58ea62f8ac05),
-which is required by the automation voice.
-
-</details>
-
-## Terminology
-
-- **message** - a [JSON](https://www.json.org)-formatted string that describes
-  some occurrence of interest, emitted at the moment it occurred; the message
-  should be a JSON object value with two string properties: `type` and `data`
-- **message type** - one of `"lifecycle"`, `"speech"`, or `"error"`
-  - `"lifecycle"` - signifies that the message data is an expected lifecycle of
-    the automation voice (e.g. initialization and destruction)
-  - `"speech"` - signifies that the message data is text which a screen reader
-    has requested the operating system annunciate
-  - `"error"` - signifies that an exceptional circumstances has occurred
-- **message data** - information which refines the meaning of the message type
-
-## Protocol
-
-This project implements [AT Driver](https://w3c.github.io/at-driver/), a
-protocol published in 2024 as [a W3C Draft Community Group
-Report](https://www.w3.org/standards/types/#CG-DRAFT). That document
-exhaustively describes the JSON-encoded WebSocket protocol. Please [file a bug
-report against this
-project](https://github.com/w3c/aria-at-automation-driver/issues/new) if you
-observe any discrepencies with AT Driver.
-
-## Architecture
-
-This tool is comprised of two main components: a text-to-speech voice and a
-WebSocket server.
-
-### Text-to-speech voice
-
-The text-to-speech voice is written in C++ and integrates with the [Microsoft
-Speech API
-(SAPI)](https://docs.microsoft.com/en-us/previous-versions/windows/desktop/ee125663(v=vs.85)).
-Because it interfaces with the Windows operating system (that is: "below" the
-screen reader in the metaphorical software stack), it can observe speech from
-many screen readers without coupling to any particular screen reader.
-
-The voice has two responsibilities. First, it emits the observed speech data
-and related events to a [Windows named
-pipe](https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes). This
-allows the second component to present a robust public interface for
-programmatic consumption of the data. (The named pipe is an implementation
-detail. Neither its content nor its presence is guaranteed, making it
-inappropriate for external use.)
-
-Second, the voice annunciates speech data. It does this by forwarding speech
-data to the system's default text-to-speech voice. This ensures that a system
-configured to use the voice remains accessible to screen reader users.
+- macOS version 13 ("Ventura") or later
+- Node.js version 18 or later
+
+## Usage
+
+1.  Run the `install` sub-command in a terminal:
+
+        at-driver install
+
+    If prompted for system administration permission, grant permission.
+
+2.  Start the server by executing the `serve` sub-command in a terminal:
+
+        at-driver serve
+
+    The process will write a message to the standard error stream when the
+    WebSocket server is listening for connections. The `--help` flag will cause
+    the command to output advanced usage instructions (e.g. `at-driver --help`).
+
+3.  Configure any screen reader to use the text-to-speech voice named "Bocoup
+    Automation Voice."
+
+4.  Use any WebSocket client to connect to the server. The protocol is described
+    below. (The server will print protocol messages to its standard error stream
+    for diagnostic purposes only. Neither the format nor the availability of
+    this output is guaranteed, making it inappropriate for external use.)
 
 ### WebSocket server
 
@@ -92,10 +51,6 @@ For details on contributing to this project, please refer to the file named
 Licensed under the terms of the MIT Expat License; the complete text is
 available in the LICENSE file.
 
-Copyright for portions of AT Driver are held by Microsoft as part of the
-"Sample Text-to-Speech Engine and MakeVoice" project. All other copyright for
-AT Driver are held by Bocoup.
-
 ---
 
 ### [aria-at-automation](https://github.com/w3c/aria-at-automation)