feat: add game config panel UI (template, Stimulus controller, CSS)

Config panel with toggle for watched films, hint type checkboxes,
and multi-select for award types above the start game button.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

assets/controllers/game_config_controller.js

@@ -0,0 +1,41 @@
+import { Controller } from '@hotwired/stimulus';
+
+export default class extends Controller {
+    static targets = ['hintType', 'awardSection', 'allAwards', 'awardType'];
+
+    toggleAwardSection() {
+        const awardChecked = this.hintTypeTargets.find(
+            (el) => el.name === 'hint_award'
+        )?.checked;
+
+        this.awardSectionTarget.style.display = awardChecked ? '' : 'none';
+    }
+
+    toggleAllAwards() {
+        const checked = this.allAwardsTarget.checked;
+        this.awardTypeTargets.forEach((el) => {
+            el.checked = checked;
+        });
+    }
+
+    syncAllAwards() {
+        const allChecked = this.awardTypeTargets.every((el) => el.checked);
+        this.allAwardsTarget.checked = allChecked;
+    }
+
+    hintTypeTargetConnected() {
+        this.#bindMinOneChecked();
+    }
+
+    #bindMinOneChecked() {
+        this.hintTypeTargets.forEach((el) => {
+            el.addEventListener('change', () => {
+                const checked = this.hintTypeTargets.filter((e) => e.checked);
+                if (checked.length === 0) {
+                    el.checked = true;
+                }
+                this.toggleAwardSection();
+            });
+        });
+    }
+}