Replace example shows with numbered production shows and add sparkle flag

- Rename all show .txt files with NNN_ numeric prefix so order is explicit
  and controlled by filename (001_heartbeat_red through 006_party)
- Drop HOME_SHOW special-casing from convert_all.py; show 0 is simply the
  lowest-numbered file
- Add SHOW_FLAG_SPARKLE support: shows can declare '// flags: sparkle' to
  overlay random white flashes on top of the base color each frame
- Wire sparkle into led_controller and config.h (SPARKLE_CHANCE/FRAMES)
- Replace old placeholder/example shows with the six production shows

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

converter/shows/001_heartbeat.txt

@@ -1,29 +0,0 @@
-// Monster Hunter cosplay — heartbeat intro
-// Three heartbeats in bright red, then fades into the base color of the breathing show.
-// Auto-advances to 002_breath_red when done.
-//
-// mode: single
-// Format: #RRGGBB, duration_ms
-
-#050000,    0   // start near black
-
-// beat 1
-#d10e29,  120   // lub — fast rise to bright red
-#300000,  100   // dip between beats
-#d10e29,  100   // dub
-#050000,  700   // rest
-
-// beat 2
-#d10e29,  120   // lub
-#300000,  100   // dip
-#d10e29,  100   // dub
-#050000,  700   // rest
-
-// beat 3
-#d10e29,  120   // lub
-#300000,  100   // dip
-#d10e29,  100   // dub
-#050000,  700   // rest
-
-// 2-second fade into the base color of the breathing show
-#99283a, 2000

converter/shows/001_heartbeat_red.txt

@@ -0,0 +1,23 @@
+// Red Heartbeat × 2 then Red Breathing — 2 lub-dub beats, then slow breathing, repeat.
+//
+// mode: single
+
+#050000,    0   // start near black
+
+// beat 1
+#d10e29,  120   // lub — fast rise to bright red
+#300000,  100   // dip between beats
+#d10e29,  100   // dub
+#050000,  600   // rest
+
+// beat 2
+#d10e29,  120   // lub
+#300000,  100   // dip
+#d10e29,  100   // dub
+#050000,  600   // rest into breathing
+
+// beat 3
+#d10e29,  120   // lub
+#300000,  100   // dip
+#d10e29,  100   // dub
+#050000,  600   // rest into breathing

converter/shows/002_breath_red.txt

@@ -1,10 +0,0 @@
-// Monster Hunter cosplay — breathing red
-// Slow breathing between dark maroon (#99283a) and bright red (#d91e1e).
-// One breath cycle lasts 5 seconds. Loops continuously.
-//
-// mode: loop
-// Format: #RRGGBB, duration_ms
-
-#99283a,    0   // snap to dim base color
-#d91e1e, 2500   // breathe in — slow rise to bright red
-#99283a, 2500   // breathe out — slow fall back to dim

converter/shows/002_heartbeat_breathe.txt

@@ -0,0 +1,7 @@
+// Red Heartbeat × 2 then Red Breathing — 2 lub-dub beats, then slow breathing, repeat.
+//
+// mode: loop
+
+// breathing
+#d10e29, 3600   // fade up to bright red
+#050000, 3600   // fade back down to near black

converter/shows/003_blue_sparkle.txt

@@ -0,0 +1,10 @@
+// Blue breath with sparkle overlay
+//
+// flags: sparkle
+// mode: loop
+
+#050018,    0   // snap to near-black blue
+#2020FF, 2500   // breathe in — slow rise to bright blue
+#2020FF,  400   // hold at peak
+#050018, 2500   // breathe out — slow fall to near-black
+#050018,  800   // pause before next breath

converter/shows/003_solid_red.txt

@@ -1,8 +0,0 @@
-// Monster Hunter cosplay — solid deep red
-// Constant dark maroon (#99283a). Stays on until the button is pressed.
-//
-// mode: loop
-// Format: #RRGGBB, duration_ms
-
-#99283a,    0   // snap on instantly
-#99283a, 30000  // hold (30s loop is invisible — same color each cycle)

converter/shows/004_pulse_yellow.txt

@@ -0,0 +1,7 @@
+// Yellow pulse — slow breathing effect
+//
+// mode: loop
+
+#202000,    0   // start at dim yellow
+#FFFF00, 1200   // fade up to bright yellow
+#202000, 1200   // fade back down to dim yellow

converter/shows/005_green_static.txt

@@ -0,0 +1,6 @@
+// Solid green
+//
+// mode: loop
+
+#00CC00,    0   // snap to green
+#00CC00, 5000   // hold (fade from green to green is invisible)

converter/shows/006_party.txt

@@ -0,0 +1,22 @@
+// Party mode — rapid rainbow color flashes
+// Plays once then auto-advances to the next show.
+//
+// mode: single
+
+#FF0000,    0   // snap to red
+#FF0000,  150   // hold red
+#FF8800,    0   // snap to orange
+#FF8800,  150   // hold orange
+#FFFF00,    0   // snap to yellow
+#FFFF00,  150   // hold yellow
+#00FF00,    0   // snap to green
+#00FF00,  150   // hold green
+#00FFFF,    0   // snap to cyan
+#00FFFF,  150   // hold cyan
+#0000FF,    0   // snap to blue
+#0000FF,  150   // hold blue
+#FF00FF,    0   // snap to magenta
+#FF00FF,  150   // hold magenta
+#FFFFFF,    0   // snap to white
+#FFFFFF,  150   // hold white
+#000000,  500   // fade to off — brief pause before advancing

converter/shows/blue_breath.txt

@@ -1,12 +0,0 @@
-// Blue breath — home / reset show (always index 0)
-// A slow, natural breathing effect in deep blue.
-// Loops continuously as the default show.
-//
-// mode: loop
-// Format: #RRGGBB, duration_ms
-
-#050018,    0   // snap to near-black blue — sets the starting point
-#2020FF, 2500   // breathe in — slow rise to bright blue
-#2020FF,  400   // hold at peak
-#050018, 2500   // breathe out — slow fall to near-black
-#050018,  800   // pause before next breath

converter/shows/example_fade.txt

@@ -1,12 +0,0 @@
-// Example: slow color cycle
-// Smooth fades between colors with different speeds.
-//
-// Format: #RRGGBB, duration_ms
-// duration_ms = time to fade FROM the previous color TO this one.
-
-#FF0000,    0   // snap to red immediately
-#00FF00, 3000   // 3 second fade to green
-#0000FF,    0   // snap to blue
-#FF00FF, 2000   // 2 second fade to purple
-#FF8000, 1000   // 1 second fade to orange
-#000000, 5000   // 5 second slow fade to off

converter/shows/example_party.txt

@@ -1,24 +0,0 @@
-// Example: party mode — rapid color flashes
-//
-// Trick: to HOLD a color for N ms, add a second step with the same color
-// and set that step's duration to N. The "fade from red to red" is invisible.
-//
-// Format: #RRGGBB, duration_ms
-
-#FF0000,    0   // snap to red
-#FF0000,  150   // hold red 150ms
-#FF8800,    0   // snap to orange
-#FF8800,  150   // hold orange 150ms
-#FFFF00,    0   // snap to yellow
-#FFFF00,  150   // hold yellow 150ms
-#00FF00,    0   // snap to green
-#00FF00,  150   // hold green 150ms
-#00FFFF,    0   // snap to cyan
-#00FFFF,  150   // hold cyan 150ms
-#0000FF,    0   // snap to blue
-#0000FF,  150   // hold blue 150ms
-#FF00FF,    0   // snap to magenta
-#FF00FF,  150   // hold magenta 150ms
-#FFFFFF,    0   // snap to white
-#FFFFFF,  150   // hold white 150ms
-#000000,  500   // fade to off — brief pause before looping

converter/shows/example_pulse.txt

@@ -1,10 +0,0 @@
-// Example: slow red pulse / heartbeat effect
-//
-// Fades from dim red to bright red and back, repeating.
-// Shows how to create an organic-feeling breathing effect.
-//
-// Format: #RRGGBB, duration_ms
-
-#200000,    0   // start at dim red (no fade — sets the initial state)
-#FF0000, 1200   // fade up to bright red
-#200000, 1200   // fade back down to dim red