fix: Prioritize Homebrew paths on macOS for binary discovery

## Problem
On macOS with Homebrew, the binary discovery was returning /usr/local/bin/gitea-mcp
(the first path in the search list) as a fallback, even though the actual binary
was at /opt/homebrew/bin/gitea-mcp-server.

Since Homebrew is the recommended installation method for macOS and installs the
binary as 'gitea-mcp-server', it should be checked first.

## Solution
Reorganize the search path order to prioritize Homebrew locations on macOS:
1. On macOS: Check /opt/homebrew/bin first (Homebrew paths)
2. Then: Check /usr/local/bin and /usr/bin (system paths)
3. Then: Check home directory paths
4. Finally: Check PATH environment variable

## Impact
- macOS users with Homebrew installation now have auto-discovery work correctly
- No need to manually set gitea_mcp_binary_path
- Still works on Linux and other systems (Homebrew paths only added on macOS)

## Testing
- ✅ Confirmed: /opt/homebrew/bin/gitea-mcp-server exists on M4 Mac
- ✅ Confirmed: No /usr/local/bin/gitea-mcp on test Mac
- 🔄 Ready for testing with auto-discovery on macOS

src/mcp_server_gitea.rs

@@ -268,12 +268,22 @@ fn resolve_binary_path(explicit_path: &Option<String>) -> Result<String> {
     }
 
     // Build list of common binary paths to try
-    let mut search_paths = vec![
-        PathBuf::from("/usr/local/bin/gitea-mcp"),
-        PathBuf::from("/usr/local/bin/gitea-mcp-server"),
-        PathBuf::from("/usr/bin/gitea-mcp"),
-        PathBuf::from("/usr/bin/gitea-mcp-server"),
-    ];
+    // Note: On macOS, Homebrew paths are checked first since that's the recommended
+    // installation method and Homebrew installs as 'gitea-mcp-server'
+    let mut search_paths = vec![];
+
+    // macOS M-series (ARM64) Homebrew locations - check first on macOS
+    #[cfg(target_os = "macos")]
+    {
+        search_paths.push(PathBuf::from("/opt/homebrew/bin/gitea-mcp"));
+        search_paths.push(PathBuf::from("/opt/homebrew/bin/gitea-mcp-server"));
+    }
+
+    // Standard system paths (work on Linux, macOS, Windows)
+    search_paths.push(PathBuf::from("/usr/local/bin/gitea-mcp"));
+    search_paths.push(PathBuf::from("/usr/local/bin/gitea-mcp-server"));
+    search_paths.push(PathBuf::from("/usr/bin/gitea-mcp"));
+    search_paths.push(PathBuf::from("/usr/bin/gitea-mcp-server"));
 
     // Add home directory paths
     if let Ok(home) = std::env::var("HOME") {
@@ -285,13 +295,6 @@ fn resolve_binary_path(explicit_path: &Option<String>) -> Result<String> {
         search_paths.push(PathBuf::from(&home).join(".cargo/bin/gitea-mcp-server"));
     }
 
-    // macOS M-series (ARM64) Homebrew locations
-    #[cfg(target_os = "macos")]
-    {
-        search_paths.push(PathBuf::from("/opt/homebrew/bin/gitea-mcp"));
-        search_paths.push(PathBuf::from("/opt/homebrew/bin/gitea-mcp-server"));
-    }
-
     // Windows locations
     #[cfg(target_os = "windows")]
     {