docs: Address final Copilot review suggestions

Fixed two remaining issues from Copilot review:

1. **Document toolchain installation rationale**
   - Added detailed comment explaining why full toolchain is needed
   - Documents dependencies: util.sh, main.py, bootstrap/, templates/
   - Clarifies this is not unnecessary bloat but required functionality

2. **Add syntax highlighting to code blocks**
   - Added 'bash' language identifier to all shell command blocks
   - Improves documentation readability
   - Fixed blocks at lines 62, 74, 83, 137

3. **Update environment documentation**
   - Removed outdated references to hardcoded compiler variables
   - Updated to reflect reliance on Homebrew's superenv
   - Clarified BOOST_INCLUDE is set in wrapper, not during build

All documentation now accurately reflects the current implementation
and provides proper syntax highlighting for better user experience.

Author: sbryngelson

packaging/homebrew/HOMEBREW.md

@@ -41,25 +41,25 @@ Runtime dependencies (needed to run MFC):
 
 The formula executes the following steps during installation:
 
-1. Sets up environment variables for compilers and libraries
-2. Runs `./mfc.sh build` to compile all three binaries
-3. Installs binaries to Homebrew's bin directory
-4. Creates a wrapper script that sets up the environment
-5. Installs Python toolchain and examples
+1. Runs `./mfc.sh build` to compile all three binaries
+2. Installs binaries to Homebrew's bin directory
+3. Installs mfc.sh to libexec for script execution
+4. Installs Python toolchain (required for mfc.sh functionality)
+5. Installs examples to share directory
+6. Creates a wrapper script that sets up the environment
 
 ### Environment Configuration
 
-The formula ensures proper environment setup:
-- BOOST_INCLUDE points to Homebrew's boost installation
-- FC (Fortran compiler) is set to gfortran
-- CC (C compiler) is set to gcc
-- CXX (C++ compiler) is set to g++
+The formula relies on Homebrew's automatic environment setup:
+- Compiler flags are set via the `gcc` dependency (Homebrew's superenv)
+- Library paths are automatically configured
+- The wrapper script sets BOOST_INCLUDE at runtime for user commands
 
 ### Wrapper Script
 
 The installed `mfc` wrapper provides the complete MFC interface. It automatically configures the environment and delegates to the main `mfc.sh` script. Users can run any MFC command through this wrapper:
 
-```
+```bash
 mfc build
 mfc run examples/case.py
 mfc test
@@ -71,7 +71,7 @@ mfc clean
 ### Standard Installation
 
 Users install MFC with:
-```
+```bash
 brew install mfc
 ```
 
@@ -80,7 +80,7 @@ This fetches the source tarball from GitHub releases, verifies the checksum, and
 ### Development Installation
 
 For the latest development version:
-```
+```bash
 brew install --HEAD mfc
 ```
 
@@ -134,7 +134,7 @@ Submit a pull request to homebrew-core for inclusion in the main Homebrew reposi
 
 ### Third-Party Tap
 Create a separate tap (custom repository) for immediate availability:
-```
+```bash
 brew tap organization/mfc
 brew install organization/mfc/mfc
 ```

packaging/homebrew/mfc.rb

@@ -32,6 +32,11 @@ def install
     libexec.install "mfc.sh"
 
     # Install Python toolchain
+    # The entire toolchain directory is required because mfc.sh depends on:
+    # - util.sh for shell utilities
+    # - main.py and mfc/ for the Python CLI
+    # - bootstrap/ for build/lint/format scripts
+    # - templates/ for HPC job submission
     prefix.install "toolchain"
 
     # Install examples