fix(tree): a workspace or tab name of only spaces is no name

The rename box in the GUI trims what is typed and maps an empty result to
unnamed. The CLI did not: `tty7 ws new "  "` stored a name of spaces,
which prints as a blank cell in `ws ls` — it looks unnamed without being
unnamed, so it sorts, compares and resolves as a name nobody can see or
retype. The same door was open on rename, for tabs as well as workspaces.

Normalising in `MachineStore` rather than in each caller settles it for
both front doors at once, and for whatever is added beside them later;
the GUI's own trim becomes redundant rather than wrong. Surrounding
whitespace is dropped from names that survive, so `"  web  "` and `"web"`
are the same name rather than two.

crates/tty7-core/src/core/machine.rs

@@ -506,6 +506,23 @@ fn not_found(msg: impl Into<String>) -> io::Error {
     io::Error::new(io::ErrorKind::NotFound, msg.into())
 }
 
+/// A name the tree will keep: trimmed, and nothing left means unnamed.
+///
+/// The rename box in the GUI trims and maps an empty result to unnamed
+/// already, but the CLI handed `tty7 ws new "  "` straight through, and a
+/// workspace named with spaces prints as a blank cell — it looks unnamed
+/// without being unnamed, so it sorts, compares and resolves as a name nobody
+/// can see or retype. One rule at the store settles it for both front doors
+/// and for anything added beside them later.
+fn normalize_name(name: Option<String>) -> Option<String> {
+    let name = name?;
+    let trimmed = name.trim();
+    match trimmed.is_empty() {
+        true => None,
+        false => Some(trimmed.to_string()),
+    }
+}
+
 impl MachineStore {
     /// Open the store at `path`, reading whatever is there.
     ///
@@ -604,7 +621,7 @@ impl MachineStore {
             }
             let workspace = Workspace {
                 id: id.unwrap_or_default(),
-                name: name.clone(),
+                name: normalize_name(name.clone()),
                 ..Workspace::default()
             };
             m.workspaces.push(workspace.clone());
@@ -627,6 +644,7 @@ impl MachineStore {
         name: Option<String>,
         origin: Option<SubscriberId>,
     ) -> io::Result<()> {
+        let name = normalize_name(name);
         self.mutate(origin, |m| {
             let ws = find_workspace(m, id)?;
             ws.name = name.clone();
@@ -754,6 +772,7 @@ impl MachineStore {
         name: Option<String>,
         origin: Option<SubscriberId>,
     ) -> io::Result<()> {
+        let name = normalize_name(name);
         self.mutate(origin, |m| {
             let t = find_tab(m, workspace, tab)?;
             t.name = name.clone();
@@ -2035,6 +2054,40 @@ mod tests {
         }
     }
 
+    #[test]
+    fn a_name_that_is_only_spaces_is_no_name() {
+        let (store, _dir) = store();
+        // The GUI's rename box trims and maps empty to unnamed; `tty7 ws new
+        // "  "` used to get a workspace whose name printed as a blank cell,
+        // which looks unnamed without being unnamed.
+        let ws = store
+            .workspace_create(None, Some("   ".into()), None)
+            .unwrap();
+        assert_eq!(ws.name, None, "a name of spaces is not a name");
+
+        let named = store
+            .workspace_create(None, Some("  web  ".into()), None)
+            .unwrap();
+        assert_eq!(
+            named.name.as_deref(),
+            Some("web"),
+            "surrounding space is dropped"
+        );
+
+        store
+            .workspace_rename(named.id, Some(" \t ".into()), None)
+            .unwrap();
+        assert_eq!(store.workspace(named.id).unwrap().name, None);
+
+        store
+            .workspace_rename(named.id, Some(" api ".into()), None)
+            .unwrap();
+        assert_eq!(
+            store.workspace(named.id).unwrap().name.as_deref(),
+            Some("api")
+        );
+    }
+
     #[test]
     fn workspace_create_rename_touch_delete_land_and_broadcast() {
         let (store, _dir) = store();