A ribbon tool that opens a popup window (LAYERS, PAGESETUP,
ABOUT, the style managers, …) marks itself blue via
\`activate_tool\` when the user clicks it, but nothing un-marked
the tool after the window was dismissed — \`OsWindowClosed\`
cleared the matching \`_window\` slot, the active-tool string
stayed put, and the button kept rendering as if the panel were
still open.
Add \`Ribbon::deactivate_tool_if(id)\` (clears only when the
active tool matches) and call it for every popup-window slot in
\`OsWindowClosed\`. Also clear inside the \`ToggleLayers\` close
branch — that path \`take()\`s \`layer_window\` to \`None\` before
\`OsWindowClosed\` fires, so the conditional in the
\`OsWindowClosed\` handler would miss the close otherwise.
Mapped IDs match the matching ribbon \`ToolDef.id\`s (LAYERS,
PAGESETUP, ABOUT) plus command names for the popups normally
opened via the command line (TEXTSTYLE, TABLESTYLE, MLSTYLE,
LAYOUTMANAGER / LAYOUTPANEL, PLOTSTYLE / STYLESMANAGER, DIMSTYLE,
SHORTCUTS / KEYBOARD) so a future ribbon tool with one of those
ids gets the same correct deactivate.
Closes#40