README: drop center alignment, document macOS

- Drop the outer <div align="center"> wrapping the whole file. Markdown
  bodies are conventionally left-aligned; centering the install
  instructions made the prose harder to scan and didn't actually render
  cleanly across viewers (GitHub honors it; many editors don't).
- Keep a small <p align="center"> just around the logo image where
  centering is what you actually want.
- Add a proper top-level title (# OrcaSlicer — BambuNetwork edition)
  instead of leaning on a level-2 heading for the intro.
- Replace the macOS "Work in progress" placeholder with a description
  of the auto-install flow (Lima + qemu x86_64 Linux guest) and what
  the user has to do on first launch — essentially: confirm the
  install prompt and wait a few minutes the first time.
- Mention that ./build_release_macos.sh now defaults to Ninja with
  -x as the Xcode opt-in, in case anyone has the inverse muscle memory
  from upstream.
- Light prose tidy throughout (single-sentence platform notes, fewer
  hard line breaks).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: stephanGarland

README.md

@@ -1,21 +1,20 @@
-<div align="center">
+<p align="center">
+  <img alt="OrcaSlicer logo" src="resources/images/OrcaSlicer.png" width="15%">
+</p>
 
-<picture>
-  <img alt="OrcaSlicer logo" src="resources/images/OrcaSlicer.png" width="15%" height="15%">
-</picture>
+# OrcaSlicer — BambuNetwork edition
 
-## This version of OrcaSlicer restores full BambuNetwork support for Bambu Lab printers.
-
-You are not limited to LAN only.  
-It works over the internet just like before, through BambuNetwork, with full functionality for normal use and printing.
+This version of OrcaSlicer restores full BambuNetwork support for Bambu Lab
+printers. You are not limited to LAN only — it works over the internet just
+like before, through BambuNetwork, with full functionality for normal use
+and printing.
 
 ## Installation
 
 ### Windows
 
-Windows requires WSL 2.
-
-Before first launch, open Command Prompt or PowerShell as Administrator and run:
+Windows requires WSL 2. Before the first launch, open Command Prompt or
+PowerShell as Administrator and run:
 
 ```bat
 dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart
@@ -26,17 +25,35 @@ Restart Windows, then launch Orca Studio.
 
 ### Linux
 
-On Linux, a normal installation is enough.
+A normal installation is enough.
 
 ### macOS
 
-Work in progress.
+Supported on both Apple Silicon and Intel. On first launch OrcaSlicer
+auto-installs a small Lima VM (`orcaslicer-bambu-network`) that runs the
+Linux BambuNetwork plug-in under a native x86_64 Linux guest. You'll be
+prompted to install the runtime when you launch the app for the first
+time; accepting will:
 
+- install Lima and `qemu-system-x86_64` via Homebrew if they're missing,
+- bring up an Ubuntu x86_64 VM in the background,
+- copy the BambuNetwork payload into the VM.
 
-## BMCU
+Once the runtime is ready, log in to Bambu Cloud normally — printers,
+camera preview, and Send-to-Printer (cloud or LAN) all work as on other
+platforms.
 
-I also encourage you to use BMCU.
+Notes:
 
-You can find BMCU firmware in my repositories.
+- The first runtime install downloads an Ubuntu cloud image and takes a
+  few minutes; subsequent launches are immediate.
+- Building from source on macOS 15 (Tahoe) is supported via
+  `./build_release_macos.sh`. Ninja is the default generator; `-x`
+  switches to the Xcode generator if you have a full Xcode.app install.
+
+## BMCU
 
-</div>
+The BMCU companion firmware is also encouraged. The firmware lives in a
+separate repository in the upstream maintainer's account.
+</content>
+</invoke>