fix(clients): GTK + Decky polish batch from live Deck/Windows testing

GTK Linux client:
- hosts/library: clicking a card was dead — the handler was on
  FlowBoxChild::activate (never emitted on click); bridge child-activated
  → child.activate() on the FlowBox (ui_hosts, ui_library).
- stream: the Ctrl+Alt+Shift+D/Q/S chords (and all key forwarding) were
  dropped because the key controller sat on the overlay, which loses focus
  to the header back button after nav.push+fullscreen — move it to the
  window and remove it on teardown.
- video: a mid-session VAAPI decode error rebuilt a software decoder but
  never requested a keyframe, so under the infinite GOP the picture stayed
  gray/frozen forever. Request an IDR on any VAAPI error, keep the hardware
  decoder, and demote to software only after repeated failures.
- stream: fix a per-session Capture↔overlay reference cycle that leaked the
  overlay subtree + the Arc<NativeClient> on every session end — hold the
  overlay weakly.
- stream: accumulate the fractional wheel remainder so precision-scroll
  (Deck trackpad / hi-res wheels) sub-unit deltas aren't dropped.
- gamepad library: keep the launcher smooth on the Deck — freeze the aurora
  and trim the visible card range (fewer 3D offscreen passes) on low-power.
- gamepad: log full pad identity (vid:pid:name:type:virtual) on attach to
  diagnose an empty controller list on the Deck.
- cli: --connect host:<badport> silently did nothing; default to 9777 + warn.
- css: add the missing .pf-neutral pill rule; fix the clipped most-recent
  accent (inset outline instead of a corner-clipped box-shadow bar).

Decky plugin:
- surface the on-screen library browser: label the host-row Games button.
- fix silent pin data-loss — the detached Games modal captured a frozen
  pins array, so pinning a second game clobbered the first; mirror pins in
  a ref and track the modal's pinned ids locally for a live label.
- route pair-required hosts through the pairing modal from the fullscreen
  Stream button (parity with the QAM panel).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/decky/src/library.tsx

@@ -95,6 +95,24 @@ export const GamePickerModal: FC<{
 }> = ({ host, pins, clientUpdatePending, closeModal }) => {
   const [result, setResult] = useState<LibraryResult | null>(null);
   const [attempt, setAttempt] = useState(0); // bump to refetch (retry / after pairing)
+  // The modal is a detached `showModal` portal that never re-renders from the page's pin
+  // state, so `pins.isPinned` would read a frozen snapshot and the Pin/Unpin label would
+  // never flip within a session. Track this host's pinned ids locally, seeded once from the
+  // snapshot at open; persistence still goes through the (stale-closure-safe) pins API.
+  const [pinnedIds, setPinnedIds] = useState<Set<string>>(
+    () => new Set(pins.pins.filter((p) => p.host_fp === host.fp).map((p) => p.game_id)),
+  );
+  const togglePin = (g: GameEntry) => {
+    const wasPinned = pinnedIds.has(g.id);
+    setPinnedIds((prev) => {
+      const next = new Set(prev);
+      if (wasPinned) next.delete(g.id);
+      else next.add(g.id);
+      return next;
+    });
+    if (wasPinned) pins.removePin(host.fp, g.id);
+    else pins.addPin(host, g);
+  };
 
   useEffect(() => {
     let stale = false;
@@ -188,7 +206,7 @@ export const GamePickerModal: FC<{
       {sorted.length > 0 && (
         <div style={{ maxHeight: "55vh", overflowY: "auto" }}>
           {sorted.map((g: GameEntry) => {
-            const pinned = pins.isPinned(host.fp, g.id);
+            const pinned = pinnedIds.has(g.id);
             const safe = isSafeLaunchId(g.id);
             return (
               <Field
@@ -199,13 +217,7 @@ export const GamePickerModal: FC<{
                 }
                 childrenContainerWidth="max"
               >
-                <DialogButton
-                  style={pickButton}
-                  disabled={!safe}
-                  onClick={() =>
-                    pinned ? pins.removePin(host.fp, g.id) : pins.addPin(host, g)
-                  }
-                >
+                <DialogButton style={pickButton} disabled={!safe} onClick={() => togglePin(g)}>
                   <FaThLarge style={{ marginRight: "0.4em" }} />
                   {pinned ? "Unpin" : "Pin"}
                 </DialogButton>