Sell PRO as an in-app unlock, take shared photos, and let FX run negative

- One free Play app (com.locphamtran.recipescamera) with an expo-iap PRO
  unlock, replacing the paid apk for the store channel
- Android SEND/SEND_MULTIPLE share target feeds photos into the editor,
  on cold start and on resume
- BACK button in the TopBar and press-and-hold PEEK replace the chip row
- NOISE REDUCTION and SHARPENING accept -10: a negative SHARPENING softens
  the frame before the grain pass, a negative NOISE REDUCTION re-grains it,
  in the Skia engine, the live preview and the Kotlin export path alike

src/utils/entitlement.ts

@@ -1,14 +1,10 @@
 import { FrameId } from '../types';
-import { IS_PRO_BUILD } from '../provariant';
 
-// LITE (free) vs PRO (the paid build). The two are separate apks built from this
-// one tree: the tier is fixed at build time by src/provariant.ts (rewritten by
-// tools/set-variant.mjs, `npm run apk:lite|apk:pro`) and nothing in a LITE apk
-// can change it afterwards — no key, no server, no stored flag.
-
-// Constant for the life of the build, so every `!IS_PRO` branch below is dead
-// code the bundler is free to drop.
-export const IS_PRO = IS_PRO_BUILD;
+// LITE (free) vs PRO. Two apks come out of this one tree: the PRO apk
+// (src/provariant.ts, rewritten by tools/set-variant.mjs) is born owned, while
+// the LITE apk is the free build and buys the tier through Google Play. The
+// tier itself is runtime state, so it lives in src/utils/proUnlock.ts and every
+// caller takes it from there (useProUnlock) or by prop.
 
 // The gate is on the FILE, not on the preview: a LITE user composes with any
 // look and compares it before/after — only the render/export of a PRO look is