feat: take the store root as an option

src/cli/link.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use clap::Subcommand;
+use clap::{Args, Subcommand};
 
 #[derive(Subcommand, Debug)]
 pub enum Link {
@@ -13,6 +13,9 @@ pub enum Link {
         /// Link to a store path that already exists
         #[arg(long)]
         force: bool,
+
+        #[command(flatten)]
+        store: Store,
     },
 
     /// Move paths in the store back into the repository
@@ -22,6 +25,9 @@ pub enum Link {
         /// Restore every path this repository has in the store
         #[arg(long)]
         all: bool,
+
+        #[command(flatten)]
+        store: Store,
     },
 
     /// List untracked paths a sandbox would still see
@@ -40,5 +46,17 @@ pub enum Link {
         /// Terminate porcelain entries with NUL
         #[arg(short = 'z')]
         null: bool,
+
+        #[command(flatten)]
+        store: Store,
     },
 }
+
+#[derive(Args, Debug)]
+pub struct Store {
+    /// Where the out-of-repo store lives
+    ///
+    /// Defaults to `${XDG_DATA_HOME:-$HOME/.local/share}/ahab`.
+    #[arg(long = "store", env = "AHAB_LINK_ROOT", value_name = "DIR")]
+    pub root: Option<PathBuf>,
+}