TUI: explorer context menu doesn't auto-dismiss after clicking an entry

[JDonaghy]

Problem

Right-clicking a file in the TUI explorer opens the context menu correctly (#451 fixed this), but clicking an entry in the menu executes the action without dismissing the menu. The menu stays visible after the action fires.

This is a regression on latest develop — the dismiss path was working after #451 landed but broke in a subsequent merge (likely #452 group divider drag changes to src/tui_main/mouse.rs).

Reproduction

1. Open TUI vimcode
2. Right-click a file in the explorer sidebar
3. Context menu appears (correct)
4. Click an entry (e.g., "Open to the Side")
5. Expected: action fires AND menu dismisses
6. Actual: action fires but menu stays visible

Likely cause

#452 (group divider drag) modified click dispatch in src/tui_main/mouse.rs. The context menu click handler may no longer call engine.close_context_menu() after executing the action, or the hit-test path changed so the dismiss branch is skipped.

Files

• src/tui_main/mouse.rs — context menu click dispatch
• Possibly src/core/engine/ — close_context_menu() or handle_context_menu_click()

[JDonaghy]

Prior art

• ContextMenu: motion handlers should use primitive's hit_test, not hand-rolled row math #210 — context menu click/hover via cached ContextMenuLayout::hit_test() (commit 35a9c42)
• TUI: right-click on explorer does nothing (engine state opens but menu doesn't render or dispatch) #451 — TUI right-click opening fixed (commits 15d6ace, 28cd07c)
• TUI: resize between tab groups (vertical-split editor divider drag) broken #452 — group divider drag fix in mouse.rs — likely where the dismiss path broke

The dismiss-on-click was implicit in the click dispatch order, not an explicit feature. Check the #452 diff in src/tui_main/mouse.rs for changes to the click handler ordering that might skip the context menu hit-test branch.

[JDonaghy]

Implementation notes (2026-05-17, coordinator)

Hot zone warning: src/tui_main/mouse.rs was modified by #451 (ctx menu open) and #452 (divider drag) in the last few hours. This regression was introduced by one of those. Check the #452 diff specifically — it likely shifted the click dispatch order so the context menu hit-test branch is skipped or doesn't call close_context_menu() after executing.

After fixing, verify these still work (recent fixes in the same file):

• Right-click explorer → ctx menu opens (TUI: right-click on explorer does nothing (engine state opens but menu doesn't render or dispatch) #451)
• Drag group divider → groups resize (TUI: resize between tab groups (vertical-split editor divider drag) broken #452)
• Click ctx menu entry → action fires AND menu dismisses (this issue)

Files: src/tui_main/mouse.rs — context menu click dispatch path.

Do NOT touch: src/gtk/, src/render.rs.