feat(#2621): tighten bash task names to a valid ident ([a-z0-9-])

hive-bash-mcp/src/bin/mcp.rs

@@ -190,8 +190,9 @@ struct BashRunArgs {
     /// in `status` lookups and your loose-ends list — handy for recognising
     /// a task later instead of an opaque hex id. A name can be reused once
     /// its previous task has finished; reusing a name whose task is still
-    /// running is rejected. Allowed chars: ASCII letters, digits, `.`,
-    /// `_`, `-` (max 64). Omit to get the auto-generated id.
+    /// running is rejected. Allowed chars: `[a-z0-9-]` (a valid
+    /// identifier — lowercase, digits, hyphen; max 63). Omit to get the
+    /// auto-generated id.
     #[serde(default)]
     name: Option<String>,
 }