fix(tui): address review feedback

tests/test_tui_gateway_server.py

@@ -356,6 +356,9 @@ def test_complete_slash_includes_tui_details_command():
 
 
 def test_complete_slash_details_args():
+    resp_root = server.handle_request(
+        {"id": "0", "method": "complete.slash", "params": {"text": "/details"}}
+    )
     resp_section = server.handle_request(
         {"id": "1", "method": "complete.slash", "params": {"text": "/details t"}}
     )
@@ -367,6 +370,7 @@ def test_complete_slash_details_args():
         }
     )
 
+    assert resp_root["result"]["replace_from"] == len("/details")
     assert any(item["text"] == "thinking" for item in resp_section["result"]["items"])
     assert any(item["text"] == "expanded" for item in resp_mode["result"]["items"])
 

tui_gateway/server.py

@@ -3822,7 +3822,10 @@ def _(rid, params: dict) -> dict:
         if details_items is not None:
             return _ok(
                 rid,
-                {"items": details_items, "replace_from": text.rfind(" ") + 1},
+                {
+                    "items": details_items,
+                    "replace_from": text.rfind(" ") + 1 if " " in text else len(text),
+                },
             )
 
         return _ok(

ui-tui/src/__tests__/textInputWrap.test.ts

@@ -42,9 +42,10 @@ describe('input metrics helpers', () => {
     expect(inputVisualHeight('one\ntwo', 40)).toBe(2)
   })
 
-  it('reserves a stable transcript scrollbar gutter for composer width', () => {
+  it('reserves gutters without exceeding the physical terminal width', () => {
     expect(stableComposerColumns(100, 3)).toBe(93)
-    expect(stableComposerColumns(10, 3)).toBe(20)
+    expect(stableComposerColumns(10, 3)).toBe(3)
+    expect(stableComposerColumns(6, 3)).toBe(1)
   })
 })
 

ui-tui/src/lib/inputMetrics.ts

@@ -54,9 +54,9 @@ export function inputVisualHeight(value: string, columns: number) {
 }
 
 export function stableComposerColumns(totalCols: number, promptWidth: number) {
-  // totalCols is the terminal width. Reserve:
+  // Physical render/wrap width. Reserve:
   // - outer composer paddingX={1}: 2 columns
   // - transcript scrollbar gutter + marginLeft: 2 columns
   // - prompt prefix width
-  return Math.max(20, totalCols - promptWidth - 4)
+  return Math.max(1, totalCols - promptWidth - 4)
 }