Add another gym about scene switching

docs/gyms/gym09_scene_switching/gym09_congrats.dtl

@@ -0,0 +1,51 @@
+# ============================================================
+# Gym 09 — Scene Switching: Congratulations Timeline
+# ============================================================
+# This timeline runs AFTER the player returns from the
+# minigame. It congratulates them and explains the mechanism.
+# ============================================================
+
+join Miko center
+join Advisor right
+
+Miko (joy): You did it! You pressed the button 5 times!
+
+[wait time="0.5"]
+
+Advisor (pl5): Welcome back to a Dialogic timeline.
+Advisor (pl5): Notice what just happened:
+
+[wait time="1.0"]
+
+Advisor (pl5): 1. You started in a Dialogic timeline (the intro).
+Advisor (pl5): 2. A signal triggered a scene change to a pure\
+gameplay scene with no Dialogic UI.
+Advisor (pl5): 3. The minigame set a Dialogic variable:\
+`Gym.minigame_done = true`
+Advisor (pl5): 4. Then it called `change_scene_to_file()` back here.
+Advisor (pl5): 5. This scene's controller checked the variable\
+and started THIS timeline.
+
+[wait time="2.0"]
+
+Miko (smile): The magic is that Dialogic is an AUTOLOAD!
+Miko (joy): Its variables survive scene changes because the\
+autoload never gets freed.
+
+Advisor (doubt): This pattern is essential for:
+Advisor (doubt): • Minigames (fishing, crafting, lockpicking)
+Advisor (doubt): • Combat encounters between dialog scenes
+Advisor (doubt): • Exploration that triggers narrative beats
+Advisor (doubt): • Any gameplay/dialog hybrid
+
+[wait time="2.0"]
+
+Miko (smile): Want to try again?
+
+- Yes, play the minigame again!
+    set {Gym.minigame_done} = false
+    [signal arg=start_minigame]
+
+- No, I understand the pattern. Back to hub.
+    set {Gym.minigame_done} = false
+    jump gym_main/menu