ui: round 6 — Enter submits from anywhere; model dashes ACTUALLY kept; dumbbell right

- ENTER SUBMITS REGARDLESS OF FOCUS (owner): dictation means the dock
  fields are rarely focused. New useEnterSubmits hook — a window-level
  listener inside both docks (mounted only while a problem/question is
  active). Plain Enter anywhere outside a typing surface submits the
  practice thinking / the teaching answer; typing surfaces keep their
  own handlers, buttons keep their click-activation (the collapsed
  Problem bar still expands on Enter), modified Enters untouched.
  Teaching sessions get the same law as practice — one standard.
- MODEL DASHES: the round-5 join("-") edit never landed (the batch
  script aborted on an earlier assert before reaching it) — the source
  still joined with spaces while the commit message claimed otherwise.
  Now actually joined with dashes: 'glm-5.3-flash' everywhere (picker,
  setup dialog, stats bar); pins updated to match.
- SIDEBAR: the practice dumbbell moves to the far right of the session
  row — titles sit flush with teaching rows, cleaner list.

tests/render-settings.test.tsx

@@ -155,7 +155,7 @@ describe("AgentSection (thin SSR)", () => {
 		);
 		// The trigger shows the stored id even with no catalog loaded (a
 		// trigger reading "Default" over a live override would lie).
-		assert.ok(html.includes("glm 4.7 flash"), "the override id is visible (prettyModel form, no auto-caps)");
+		assert.ok(html.includes("glm-4.7-flash"), "the override id is visible (prettyModel form, no auto-caps)");
 		assert.ok(tagOf(html, "toggle-tool-demo").includes('aria-checked="false"'), "demo off");
 		assert.ok(tagOf(html, "toggle-tool-visual").includes('aria-checked="true"'), "visual still on");
 	});