feat: add Scope controls and conditional HUD text backplates (#1410)

* feat: add scope controls and conditional HUD backplates

* docs: assign scope changelog to PR 1410

* fix: stabilize title backplate and brighten secondary labels

---------

Co-authored-by: Bilawal Sidhu <[email protected]>

docs/CURRENT-STATE.md

@@ -196,6 +196,23 @@ Regression coverage lives in `src/tools/area.test.mjs`,
 `src/tools/queries/environment.test.mjs` and
 `src/layers/perimeters/cards.test.mjs`.
 
+## Scope display controls
+
+Display's native Scope checkbox defaults ON with feather at 100%, adjustable
+from 0–200%. OFF disables the slider while retaining its value. HUD layout
+changes preserve both settings; share links and scenes restore them. The
+historical missing-`scf` fallback remains 35%; explicit 0% keeps the hard edge.
+
+With Scope OFF, Tactical, Operator and Minimal add text-sized black backplates
+at 70% opacity behind telemetry, vertical metadata and scene chrome. Original
+HUD text color, glow and opacity are preserved. Scope OFF brightens the tagline
+and Active Style label with the shared secondary text color. The title plate
+covers the eye and title without moving the title or tagline. Scope ON retains
+the original HUD presentation; Cyber retains its existing skin.
+
+`node scripts/qa-scope-hud.mjs` checks native input, range, layout persistence,
+restoration and both Scope presentations. `QA_SCREENSHOT_DIR` saves screenshots.
+
 ## Cyber HUD — September 30, 2026
 
 Display > HUD > Layout includes Cyber, also available through the HUD voice
@@ -5545,10 +5562,11 @@ the `_detectionUserOverridden` / explicit-intent flags that would suppress a
 separate landed behaviour. Pinned in `src/reasonableDefaults.test.mjs` (feather,
 detection, OUTSIDE opacity) and `src/data/layerState.test.mjs` (3D).
 
-**The 2026-08-24 defaults** (superseding the interim 08-23 values of 8%/3%):
+**Current defaults** (scope feather revised to 100% on 2026-10-25;
+detection and outside opacity retain the 2026-08-24 defaults):
 the first-run look is Detection DENSE
-`75%`, ELASTIC allocation, Fade `7%`, OUTSIDE opacity `1%`, scope feather `11%`,
-and 3D fleet mode PROXIMITY, with `AIRCRAFT_BRACKET_FLOOR_ANCHOR` at `0.01` so
+`75%`, ELASTIC allocation, Fade `7%`, OUTSIDE opacity `1%`, Scope ON with feather
+`100%`, and 3D fleet mode PROXIMITY, with `AIRCRAFT_BRACKET_FLOOR_ANCHOR` at `0.01` so
 brackets keep their approved brightness exactly at the new OUTSIDE default. Two
 terms that must never be conflated: scope FEATHER softens the black scope-mask
 edge; detection FADE is the label/card fading band around the keyhole. The
@@ -5618,14 +5636,10 @@ easier to meet (detection is now on more often), but does not create it.
   calibrated so `AIRCRAFT_BRACKET_ALPHA_FLOOR` (0.35) lands exactly at the
   default, and the mapping follows bracket brightness rather than slider
   position. The `ko` PARSE fallback stays at `5`.
-- **Scope feather: `11%`** — a soft scope-mask edge (moved `0% → 8% → 11%`; `0%` hard crop for one day,
-  `35%` before that). `SCOPE_FEATHER_RATIO_DEFAULT` in `src/scopeMask.js`,
-  mirrored by `#scope-feather-slider`'s markup value AND readout and
-  `_scopeFeatherPct` in `sharelink.js`. The slider is untouched and still spans
-  0–100, and an explicit `0` is still the hard-crop path — pinned, so moving the
-  default cannot quietly delete it. The `scf` PARSE fallback deliberately stays
-  at `35`: a link predating `scf` was authored when 35 was what its author saw,
-  and restoring the author's view is what a share link is for.
+- **Scope: `ON`, feather: `100%`**. `SCOPE_FEATHER_RATIO_DEFAULT` in
+  `src/scopeMask.js` matches the slider, readout and share generator. The range
+  is 0–200%; explicit 0% is a hard edge. Missing-`scf` links retain the historical
+  35% parse fallback.
 - **3D aircraft models: `ON`, mode `proximity`** — see the 3D Aircraft section
   above and the DISPLAY-rail entry below (was `OFF`).
 - Style shader starting params: CRT/NVG/FLIR pixelation `1.2` (just above the native `1.0` floor); thermal/FLIR ships an optional Ironbow "Predator" palette (`palette` uniform, default `0` = accurate grayscale).