fix(co4e): section actions are text again, and "+ Mới" says it did something

* "+ Mới" / "Quản lý skill…" were full buttons, ~40px tall each — the
    loudest thing in a 230px sidebar, and three rows of height spent on
    them. The wireframe writes these as small accent text beside the
    heading; they are now 17px.

  * "+ Mới" looked broken. It was not: it replaces the canvas with a fresh
    empty flow, verified by loading a saved 3-node flow and pressing it
    (3 nodes → 0). But pressing it while the canvas ALREADY held an empty
    untitled flow produced an identical empty untitled flow — right, and
    invisible. It now focuses and selects the name field, and says
    "Flow mới — đặt tên rồi kéo agent vào canvas" in the status bar, so the
    press always has a visible result.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

i18n.py

@@ -2666,6 +2666,10 @@ STRINGS: Dict[str, Dict[str, str]] = {
         "en": "Show every flow run", "ja": "すべてのフロー実行を表示",
         "vi": "Xem toàn bộ lần chạy flow"},
     "co4e.back_to_flow": {"en": "Back to flow", "ja": "フローに戻る", "vi": "Về flow"},
+    "co4e.new_flow_ready": {
+        "en": "New flow — type a name, then drag agents onto the canvas",
+        "ja": "新しいフロー — 名前を入力し、エージェントをキャンバスへ",
+        "vi": "Flow mới — đặt tên rồi kéo agent vào canvas"},
     "co4e.tt_back_to_flow": {
         "en": "Back to the flow editor", "ja": "フローエディタに戻る",
         "vi": "Quay lại màn dựng flow"},

theme.py

@@ -430,6 +430,16 @@ QTabBar#viewTabs::tab:hover { background: $hover; color: $text; }
 QTabBar#viewTabs::tab:selected { background: $active; color: $text; font-weight: 600; }
 /* Co4E sidebar section headings — same quiet caps as the rail's RECENTS, so
    "which list am I looking at" is answered on screen, not in a tooltip. */
+/* The action beside a Co4E section heading ("+ Mới", "Quản lý skill…"). The
+   wireframe writes these as small accent text; as full buttons they were the
+   loudest thing in the sidebar and each cost a row of height. */
+QPushButton#co4eSectionAction {
+    background: transparent; border: none; color: $accent;
+    font-size: 11px; font-weight: 600; padding: 1px 4px;
+    border-radius: ${radius_sm}px; qproperty-iconSize: 11px 11px;
+}
+QPushButton#co4eSectionAction:hover { background: $hover; color: $accent; }
+QPushButton#co4eSectionAction:pressed { background: $active; }
 QPushButton#co4eSectionHdr {
     color: $text_faint; font-size: 11px; font-weight: 700; letter-spacing: 0.5px;
     background: transparent; border: none; text-align: left; padding: 2px 0;

ui/co4e_tab.py

@@ -515,6 +515,9 @@ class Co4ETab(QWidget):
         self.wf_new_btn = QPushButton(tr("co4e.new"))
         self.wf_new_btn.setIcon(icon("plus"))
         self.wf_new_btn.setToolTip(tr("co4e.tt_new_wf"))
+        self.wf_new_btn.setObjectName("co4eSectionAction")
+        self.wf_new_btn.setFlat(True)
+        self.wf_new_btn.setCursor(Qt.PointingHandCursor)
         self.wf_new_btn.clicked.connect(self._new_workflow)
         wf_body = QWidget(); wl = QVBoxLayout(wf_body)
         wl.setContentsMargins(0, 0, 0, 0); wl.setSpacing(4)
@@ -545,6 +548,9 @@ class Co4ETab(QWidget):
         # --- AGENTS ------------------------------------------------------
         self.ag_new_btn = QPushButton(tr("co4e.new")); self.ag_new_btn.setIcon(icon("plus"))
         self.ag_new_btn.setToolTip(tr("co4e.tt_new_agent"))
+        self.ag_new_btn.setObjectName("co4eSectionAction")
+        self.ag_new_btn.setFlat(True)
+        self.ag_new_btn.setCursor(Qt.PointingHandCursor)
         self.ag_new_btn.clicked.connect(self._new_agent)
         ag_body = QWidget(); al = QVBoxLayout(ag_body)
         al.setContentsMargins(0, 0, 0, 0); al.setSpacing(4)
@@ -563,6 +569,9 @@ class Co4ETab(QWidget):
         # --- SKILLS ------------------------------------------------------
         self.sk_manage_btn = QPushButton(tr("co4e.manage_skills"))
         self.sk_manage_btn.setToolTip(tr("co4e.tt_manage_skills"))
+        self.sk_manage_btn.setObjectName("co4eSectionAction")
+        self.sk_manage_btn.setFlat(True)
+        self.sk_manage_btn.setCursor(Qt.PointingHandCursor)
         self.sk_manage_btn.clicked.connect(self._manage_skills)
         sk_body = QWidget(); sl = QVBoxLayout(sk_body)
         sl.setContentsMargins(0, 0, 0, 0); sl.setSpacing(4)
@@ -1199,7 +1208,14 @@ class Co4ETab(QWidget):
         self._refresh_usage_total()              # show THIS flow's token/cost total
 
     def _new_workflow(self) -> None:
-        self._open_flow(co4e.new_workflow(tr("co4e.untitled")))   # opens a new tab
+        self._open_flow(co4e.new_workflow(tr("co4e.untitled")))
+        # Pressing this while the canvas already holds an empty untitled flow
+        # produced an identical empty untitled flow — correct, and completely
+        # invisible, so the button read as broken. Say what happened and put the
+        # cursor where the next thing to do is: naming it.
+        self.name_edit.setFocus()
+        self.name_edit.selectAll()
+        self.status_message.emit(tr("co4e.new_flow_ready"))
 
     def _selected_wf(self) -> Optional[co4e.Workflow]:
         """Materialise the selected saved-flow row into a Workflow."""