fix: strip arch suffix on install, fix doubled org in github_url

- bakery: strip -x86_64 / -aarch64 / -arm64 / -armv7 suffix when placing
  binary so `breadcrumbs-x86_64` installs as `breadcrumbs`
- gen-index.sh: GH_BASE was "github.com/Breadway" but repo slugs already
  include the org, producing doubled paths; change to "github.com"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bakery/src/install.rs

@@ -12,9 +12,10 @@ pub fn install_package(pkg: &Package, bin_dir: &Path) -> Result<()> {
     // 1. Download and verify all binaries.
     let mut binary_names = Vec::new();
     for bin in &pkg.binaries {
-        let dest = bin_dir.join(&bin.name);
+        let install_name = strip_arch_suffix(&bin.name);
+        let dest = bin_dir.join(&install_name);
         fetch_and_place(bin, &dest)?;
-        binary_names.push(bin.name.clone());
+        binary_names.push(install_name.to_string());
     }
 
     // 2. Scaffold config dir + example file.
@@ -240,6 +241,16 @@ fn expand_tilde(path: &str) -> PathBuf {
     }
 }
 
+fn strip_arch_suffix(name: &str) -> &str {
+    const SUFFIXES: &[&str] = &["-x86_64", "-aarch64", "-arm64", "-armv7"];
+    for s in SUFFIXES {
+        if let Some(base) = name.strip_suffix(s) {
+            return base;
+        }
+    }
+    name
+}
+
 fn warn_path_if_needed(bin_dir: &Path) {
     let path_var = std::env::var("PATH").unwrap_or_default();
     let bin_str = bin_dir.to_string_lossy();