feat(globe): Sharpen on Navara, on at 80 % by default

The contract gains render.setSharpen({ enabled, amount }) and
render.sharpen(). Navara draws it as a custom EffectDesc: Cesium's unsharp
mask (3x3 box blur, gamma 2.2 round trip so one amount matches Cesium)
right after tone mapping and before SMAA/FXAA, skipping sky and cloud
pixels by scene depth. The Cesium engine keeps the state only; Cesium mode
still sharpens with its own post stage, unchanged. The fake engine records
it and the contract suite checks it.

Without a viewer the Sharpen slider and toggle drive the engine with the
same slider-to-amount mapping. On Navara the defaults, presets and share
links read Cesium's 49 % as 80 %.

scripts/package-boundaries.json

@@ -1770,6 +1770,7 @@
       "src/globe/navara/internals.js",
       "src/globe/navara/look.js",
       "src/globe/navara/maps.js",
+      "src/globe/navara/sharpen.js",
       "src/globe/navara/surface.js",
       "src/globe/navara/viewOptions.js",
       "src/app/engineChoice.js",