feat(panel): cascading columns, WB colour swatches, stronger HDF glow

Layout
- the panel is a cascade of columns: the rail's tabs, the tab's chips, the
  open chip's sub-chips, then the ruler. A child column no longer hides the
  column it came from (TEMP -> COLOR TEMP keeps TEMP visible); chips stack one
  per row instead of wrapping
- FRAME's WATERMARK opens its own column, so the frame chips stay put
- CREATE RECIPES gets the wide column its two-up form needs

WB colour swatches
- the ruler draws a colour box under the slider that follows the value:
  COLOR TEMP is the Kelvin colour (Tanner Helland), TINT runs green -10 ->
  neutral 0 -> magenta +10

HDF EFFECT
- knee 0.55..0.85 -> 0.45..0.75, blur 0.004+0.015n -> 0.006+0.024n of the
  width, screen alpha 0.15+0.35n -> 0.28+0.52n: a wide halo on the highlights
  instead of a hairline glow. Web copy of toneShader only — the phone keeps
  its own tuning.

Tabs
- rail order is PRESETS, FAVORITED, WB, LIGHT, FX, FRAME, CREATE RECIPES

docker/frontend/shared/utils/toneShader.ts

@@ -118,10 +118,12 @@ vec4 main(vec2 xy) {
 // are untouched) and above it every channel keeps its ratio — the hue cannot
 // drift, only the brightness blooms.
 //
-// Knee t0..t1 = 0.55..0.85: the soft end of the old hard 0.6 cut (2.5*0.6-1.5 =
-// 0), wide enough that a specular ramps in instead of clipping on/off.
-export const GLOW_T0 = 0.55;
-export const GLOW_T1 = 0.85;
+// Knee t0..t1 = 0.45..0.75. The web demo plays the effect up, so the knee sits
+// lower and wider than the phone's 0.55..0.85: the bloom now catches the bright
+// end of the midtones (a lit face, a window) instead of only true speculars,
+// which is what makes it read on a photo that has no blown white.
+export const GLOW_T0 = 0.45;
+export const GLOW_T1 = 0.75;
 
 export const GLOW_SKSL = `
 uniform shader src;