fix(editor): stabilize image generation, layer editing and controls (#6992)

* fix(editor): stabilize image workflows and editing controls

* docs(editor): add desktop and mobile visual validation evidence

* fix(editor): synchronize quick edit model events and register imagePreferences in test coordinator

* fix(settings): enforce authoritative global image-gen policy and non-admin preference persistence

- Enforce authoritative administrator global image_gen_enabled disable in get_user_setting, do_generate_image, and image_editing_provider_available, preventing non-admin user preference overrides while preserving user-disabled opt-outs and can_generate_images privilege checks across direct, gallery, and editor paths.
- Filter non-admin preference persistence in saveImagePreferences to user preference keys only (image_model, image_edit_model, image_quality), preventing global policy toggles from leaking into user preferences.
- Return accurate 200 OK Response from saveImagePreferences after fallback persistence succeeds so settings UI displays 'Saved' instead of false 403 error, while retaining visibility of real errors.
- Load per-user preferences via readImagePreferences in initImageSettings so non-admin selections persist and display correctly after page reload.
- Clear per-user model preferences on successful admin save (POST /api/auth/settings) via PUT /api/prefs/{key} with value: null to prevent stale per-user preferences from shadowing updated global settings.
- Support clearing keys in PUT /api/prefs/{key} when value is null.
- Add comprehensive Python regression tests for global-disabled/user-enabled, global-enabled/user-disabled, and authorized generation, plus Node and browser regression tests for non-admin persistence, toggle isolation, reload, and admin clearing.

* fix(settings): invalidate shared appConfig cache near auth settings write

* fix(test): isolate test_tool_policy unit suite from external model endpoint state

* fix(test): isolate web_fetch failure regression from contextual follow-up heuristics

* fix(test): isolate test_tool_policy from cross-test approval gate state

Ensure _patch_loop_basics disables TOOL_APPROVAL_GATE_ENABLED so routing tests in test_tool_policy run in the intended opt-out posture even when prior tests populate DATA_DIR with skills or untrusted context. Remove unnecessary forced_tools and contextual web mock workarounds.

* fix(settings): isolate non-admin image toggle and surface preference cleanup errors

- Restrict image generation availability toggle to admin users in imageModels.js, disabling the switch for non-admins and reverting unauthorized changes with an explicit message.
- Separate non-admin image model preference saves from global toggle updates.
- Track preference cleanup results on admin save in imagePreferences.js, propagating cleanup failures instead of ignoring them.
- Require valid preference keys on 403 fallback so toggle-only attempts reject cleanly.
- Add /api/prefs route mock to test_image_model_settings_sync_both_directions_and_survive_reopening.
- Add regression coverage for admin cleanup failures and non-admin toggle rejection.

* fix(settings): reconcile admin toggle on partial cleanup failure and report errors

- In imagePreferences.js, distinguish pre-persistence failures from post-save cleanup failures using err.globalSaved and err.phase.

- In imagePreferences.js, notify listeners of global policy updates on partial success before propagating cleanup failure.

- In imageModels.js, retain the persisted target state on admin toggle when global persistence succeeds but cleanup fails.

- In imageModels.js, reconcile admin toggle with authoritative server state via readImagePreferences() after ambiguous or partial failures.

- In imageModels.js, report partial success accurately without suppressing preference cleanup error messages.

- Add regression coverage in test_settings_save_response_ok_js.py for cleanup HTTP 500, cleanup network rejection, successful cleanup, and failed global POST.

---------

Co-authored-by: pewdiepie-archdaemon <pewdiepie-archdaemon@users.noreply.github.com>
Co-authored-by: Alexandre Teixeira <general@alexandreteixeira.dev>

static/js/editor/stroke-pipeline.js

@@ -14,19 +14,26 @@ function toolSettings(tool) {
 
 let _lastColor = null;
 let _lastTransparentColor = null;
-function transparentColor(color) {
-  if (color === _lastColor && _lastTransparentColor) return _lastTransparentColor;
-  _lastColor = color;
+function transparentColor(color, alpha = 0) {
+  const key = `${color}|${alpha}`;
+  if (key === _lastColor && _lastTransparentColor) return _lastTransparentColor;
+  _lastColor = key;
+  _lastTransparentColor = colorWithAlpha(color, alpha);
+  return _lastTransparentColor;
+}
+
+function colorWithAlpha(color, alpha) {
   if (color.startsWith('#')) {
     const raw = color.slice(1);
     const expanded = raw.length === 3 ? raw.split('').map(char => char + char).join('') : raw;
     const rgb = [0, 2, 4].map(index => parseInt(expanded.slice(index, index + 2), 16));
-    _lastTransparentColor = `rgba(${rgb.join(',')},0)`;
-    return _lastTransparentColor;
+    return `rgba(${rgb.join(',')},${alpha})`;
   }
   const match = color.match(/rgba?\(([^)]+)\)/);
-  _lastTransparentColor = match ? `rgba(${match[1].split(',').slice(0, 3).join(',')},0)` : 'rgba(0,0,0,0)';
-  return _lastTransparentColor;
+  if (!match) return `rgba(0,0,0,${alpha})`;
+  const components = match[1].split(',');
+  const originalAlpha = components.length > 3 ? Number(components[3]) : 1;
+  return `rgba(${components.slice(0, 3).join(',')},${alpha * originalAlpha})`;
 }
 
 function circleStamp(ctx, x, y, radius, softness, color, alpha, operation) {
@@ -38,8 +45,19 @@ function circleStamp(ctx, x, y, radius, softness, color, alpha, operation) {
     ctx.fillStyle = color;
   } else {
     const gradient = ctx.createRadialGradient(x, y, radius * hard, x, y, radius);
-    gradient.addColorStop(0, color);
-    gradient.addColorStop(1, transparentColor(color));
+    if (softness > 1) {
+      // Above the old maximum, remove the firm core with a progressively
+      // gentler alpha profile while keeping the selected brush diameter.
+      ctx.fillStyle = color;
+      const normalized = ctx.fillStyle;
+      for (let step = 0; step <= 16; step++) {
+        const t = step / 16;
+        gradient.addColorStop(t, transparentColor(normalized, (1 - t) ** softness));
+      }
+    } else {
+      gradient.addColorStop(0, color);
+      gradient.addColorStop(1, transparentColor(color));
+    }
     ctx.fillStyle = gradient;
   }
   ctx.beginPath();
@@ -274,6 +292,10 @@ export function createStrokePipeline({ activeLayer, getActiveMaskLayer, composit
     if (!PAINT_TOOLS.has(tool)) return;
     const layer = activeLayer();
     if (!layer) return;
+    // Pixel writes invalidate adjusted previews even when adjustment settings
+    // themselves have not changed (otherwise retouch strokes appear late).
+    layer._adjFinalKey = null;
+    layer._adjCacheKey = null;
     if (tool === 'clone') return cloneStamp(sample, layer);
     if (tool === 'heal') {
       // A healing stroke without a picked source uses the convenient local
@@ -294,7 +316,7 @@ export function createStrokePipeline({ activeLayer, getActiveMaskLayer, composit
     let operation = 'source-over';
     let color = state.color;
     let alpha = opacity * flow;
-    let softness = Math.max(0, Math.min(1, settings.softness / 300));
+    let softness = Math.max(0, Math.min(4, settings.softness / 300));
     if (tool === 'eraser') { operation = 'destination-out'; color = 'rgba(0,0,0,1)'; }
     else if (tool === 'inpaint') {
       operation = state.inpaintEraseStroke ? 'destination-out' : 'source-over';