web: a film sim is colour and tone only

The ten PHOTO STYLE sims now carry nothing but their stock's own grade, and
each is named for the stock it stands for: PROVIA, VELVIA, CLASSIC CHROME,
CLASSIC VIVID (Velvia spliced with Classic Chrome at the blue row), CLASSIC
NEGATIVE, ASTIA, ETERNA, ACROS, LC STREETLIFE CLASSIC, LC STREETLIFE VIVID.
Grain, clarity, saturation and light moves were dropped from their
`adjustments`, so a sim is a clean starting point and the general knobs read
their defaults while the look still lands on the pixels.

LC STREETLIFE VIVID keeps the one brightness step its stock needs, but as
SIM_EXPOSURE_BIAS in colorUtils rather than as an adjustment: it is folded in
where the Exposure slider applies, so the picture gets the lift and the
parameter stays at 0.

Also in this checkpoint: the watermark/GPS boxes and their colour pickers, the
WATERMARK chip column, the real admin stats, and the fix that stopped presets
from doubling and a frame from refusing to come off when a photo was reopened
(/file is the finished render, /base the editable pixels).

docker/frontend/src/engine/session.ts

@@ -26,10 +26,14 @@ export interface StudioState {
   gpsManual?: { lat: string; lng: string };
   place?: string;
   useGeotag?: boolean;
-  gpsStyle?: { color: string; showName: boolean; showTime: boolean };
+  // size/x/y are the GPS box on the photo; older sessions hold only the colour
+  // and the two switches and take the defaults for the rest.
+  gpsStyle?: { color: string; showName: boolean; showTime: boolean; size?: number; x?: number; y?: number };
   markText?: string;
   markOn?: boolean;
-  markStyle?: { color: string; size: number };
+  // x/y are fractions of the stamp the mark is drawn on (the drag box writes
+  // them straight back); older sessions hold no x/y and take the default.
+  markStyle?: { color: string; size: number; x?: number; y?: number };
 }
 
 export function loadState(): StudioState {