feat(tools): harden scheduler speed limiter logs

Modernize the Tools release surfaces for the cross-platform re-release checklist.

- make Speed Limiter presets unit-aware and persist custom removable quick presets

- keep diagnostic logging opt-in on clean installs and honor the saved log state on startup

- stage Scheduler enablement edits without discarding unsaved draft changes

- extend persisted settings and bindings for log opt-in and speed preset state

Verification:

- npm run build

- npm test -- --run src/store/useDownloadStore.test.ts

- cargo test --lib

- cargo test settings --lib

src/components/SpeedLimiterView.tsx

@@ -1,11 +1,14 @@
-import { useEffect, useState } from 'react';
-import { Gauge, Save, Zap } from 'lucide-react';
+import { useEffect, useMemo, useState } from 'react';
+import { Gauge, Plus, Save, X, Zap } from 'lucide-react';
 import { useSettingsStore } from '../store/useSettingsStore';
 import { WindowDragRegion } from './WindowDragRegion';
 import { useToast } from '../contexts/ToastContext';
 
 type SpeedUnit = 'KB/s' | 'MB/s';
 
+const MAX_LIMIT_KIB = 10_485_760;
+const MAX_LIMIT_MB = 10240;
+
 function parseLimit(limit: string, fallback: number): { value: number; unit: SpeedUnit } {
   const match = limit.trim().match(/^(\d+(?:\.\d+)?)\s*([km]?)b?(?:\/s)?$/i);
   const valueKiB = match
@@ -17,28 +20,57 @@ function parseLimit(limit: string, fallback: number): { value: number; unit: Spe
     : { value: valueKiB, unit: 'KB/s' };
 }
 
+function sanitizePresetValues(values: number[]): number[] {
+  const cleaned = values
+    .map(value => Number(value))
+    .filter(value => Number.isFinite(value) && value > 0)
+    .map(value => Math.min(MAX_LIMIT_MB, Math.round(value * 100) / 100));
+
+  return Array.from(new Set(cleaned)).sort((a, b) => a - b);
+}
+
+function presetBaseFromDisplayValue(value: number, unit: SpeedUnit): number {
+  return unit === 'MB/s' ? value : value / 1000;
+}
+
+function displayValueFromPresetBase(value: number, unit: SpeedUnit): number {
+  return unit === 'MB/s' ? value : Math.round(value * 1000);
+}
+
+function formatPresetValue(value: number): string {
+  return Number.isInteger(value) ? String(value) : value.toFixed(2).replace(/\.?0+$/, '');
+}
+
 export default function SpeedLimiterView() {
   const globalSpeedLimit = useSettingsStore(state => state.globalSpeedLimit);
   const lastCustomSpeedLimitKiB = useSettingsStore(state => state.lastCustomSpeedLimitKiB);
+  const speedLimitPresetValues = useSettingsStore(state => state.speedLimitPresetValues);
   const setGlobalSpeedLimit = useSettingsStore(state => state.setGlobalSpeedLimit);
   const setLastCustomSpeedLimitKiB = useSettingsStore(state => state.setLastCustomSpeedLimitKiB);
+  const setSpeedLimitPresetValues = useSettingsStore(state => state.setSpeedLimitPresetValues);
   const initial = parseLimit(globalSpeedLimit, lastCustomSpeedLimitKiB);
   const [enabled, setEnabled] = useState(Boolean(globalSpeedLimit));
   const [value, setValue] = useState(initial.value);
   const [unit, setUnit] = useState<SpeedUnit>(initial.unit);
+  const [customPresetValue, setCustomPresetValue] = useState(initial.value);
   const { addToast } = useToast();
+  const presetValues = useMemo(
+    () => sanitizePresetValues(speedLimitPresetValues),
+    [speedLimitPresetValues]
+  );
 
   useEffect(() => {
     const parsed = parseLimit(globalSpeedLimit, lastCustomSpeedLimitKiB);
     setEnabled(Boolean(globalSpeedLimit));
     setValue(parsed.value);
     setUnit(parsed.unit);
+    setCustomPresetValue(parsed.value);
   }, [globalSpeedLimit, lastCustomSpeedLimitKiB]);
 
 
   const save = () => {
-    const numericValue = Math.max(1, Math.min(Number(value) || 1, unit === 'MB/s' ? 10240 : 10_485_760));
-    const valueKiB = Math.min(10_485_760, Math.round(unit === 'MB/s' ? numericValue * 1024 : numericValue));
+    const numericValue = Math.max(1, Math.min(Number(value) || 1, unit === 'MB/s' ? 10240 : MAX_LIMIT_KIB));
+    const valueKiB = Math.min(MAX_LIMIT_KIB, Math.round(unit === 'MB/s' ? numericValue * 1024 : numericValue));
     setLastCustomSpeedLimitKiB(valueKiB);
     setGlobalSpeedLimit(enabled ? `${valueKiB}K` : '');
     addToast({
@@ -49,8 +81,33 @@ export default function SpeedLimiterView() {
 
   const preset = (presetValue: number) => {
     setEnabled(true);
-    setValue(presetValue);
-    setUnit('MB/s');
+    setValue(displayValueFromPresetBase(presetValue, unit));
+  };
+
+  const applyCustomPreset = () => {
+    const numericValue = Math.max(1, Math.min(Number(customPresetValue) || 1, unit === 'MB/s' ? MAX_LIMIT_MB : MAX_LIMIT_KIB));
+    const presetBaseValue = Math.min(MAX_LIMIT_MB, presetBaseFromDisplayValue(numericValue, unit));
+    const nextPresets = sanitizePresetValues([...presetValues, presetBaseValue]);
+    const alreadyExists = nextPresets.length === presetValues.length;
+    setSpeedLimitPresetValues(nextPresets);
+    setEnabled(true);
+    setValue(numericValue);
+    addToast({
+      message: alreadyExists
+        ? `${formatPresetValue(numericValue)} ${unit} is already in quick presets`
+        : `Added ${formatPresetValue(numericValue)} ${unit} quick preset`,
+      variant: alreadyExists ? 'info' : 'success'
+    });
+  };
+
+  const removePreset = (presetValue: number) => {
+    const displayValue = displayValueFromPresetBase(presetValue, unit);
+    const nextPresets = presetValues.filter(value => value !== presetValue);
+    setSpeedLimitPresetValues(nextPresets);
+    addToast({
+      message: `Removed ${formatPresetValue(displayValue)} ${unit} quick preset`,
+      variant: 'info'
+    });
   };
 
   return (
@@ -82,13 +139,12 @@ export default function SpeedLimiterView() {
       </div>
 
       <div className="flex-1 overflow-y-auto p-6">
-        <section className={`app-card max-w-[720px] p-5 ${enabled ? '' : 'opacity-50'}`}>
+        <section className={`app-card max-w-[760px] p-5 ${enabled ? '' : 'opacity-55'}`}>
           <div className="mb-2 flex items-center gap-2 font-semibold text-text-primary">
             <Gauge size={18} className="text-accent" /> Global Speed Limit
           </div>
-          <p className="max-w-xl text-[12px] leading-relaxed text-text-muted">
-            This cap is shared by transfers running through the core downloader. A lower per-download limit still takes precedence.
-            Saving updates the core downloader immediately; media extraction keeps its existing per-download options.
+          <p className="max-w-2xl text-[12px] leading-relaxed text-text-muted">
+            Applies to new and active aria2 transfers, native fallback transfers, and yt-dlp media downloads. Per-download limits still take precedence.
           </p>
 
           <div className="mt-6 flex items-center gap-3">
@@ -121,18 +177,57 @@ export default function SpeedLimiterView() {
           <div className="mb-3 flex items-center gap-2 text-[12px] font-medium text-text-secondary">
             <Zap size={14} /> Quick Presets
           </div>
-          <div className="flex flex-wrap gap-2">
-            {[1, 5, 10].map(presetValue => (
+          <div className="flex flex-wrap items-center gap-2">
+            {presetValues.map(presetValue => {
+              const displayValue = displayValueFromPresetBase(presetValue, unit);
+              return (
+                <div
+                  key={presetValue}
+                  className="group flex h-8 min-w-[92px] items-center overflow-hidden rounded-md border border-border-modal bg-bg-input text-[12px] text-text-primary transition-colors hover:bg-item-hover"
+                >
+                  <button
+                    type="button"
+                    disabled={!enabled}
+                    onClick={() => preset(presetValue)}
+                    className="h-full flex-1 px-3 text-left disabled:opacity-50"
+                  >
+                    {formatPresetValue(displayValue)} {unit}
+                  </button>
+                  <button
+                    type="button"
+                    disabled={!enabled}
+                    onClick={() => removePreset(presetValue)}
+                    className="flex h-full w-7 items-center justify-center border-l border-border-modal text-text-muted transition-colors hover:bg-red-500/10 hover:text-red-400 focus-visible:bg-red-500/10 focus-visible:text-red-400 disabled:opacity-50"
+                    title={`Remove ${formatPresetValue(displayValue)} ${unit} preset`}
+                    aria-label={`Remove ${formatPresetValue(displayValue)} ${unit} preset`}
+                  >
+                    <X size={12} />
+                  </button>
+                </div>
+              );
+            })}
+            <div className="ml-1 flex h-8 items-center gap-1.5 rounded-md border border-border-modal bg-bg-input px-2">
+              <input
+                type="number"
+                min="1"
+                value={customPresetValue}
+                disabled={!enabled}
+                onChange={event => setCustomPresetValue(Math.max(1, Number(event.target.value) || 1))}
+                className="w-12 bg-transparent text-right font-mono text-[12px] text-text-primary outline-none disabled:opacity-50"
+                aria-label={`Custom preset in ${unit}`}
+              />
+              <span className="text-[11px] text-text-muted">{unit}</span>
               <button
-                key={presetValue}
                 type="button"
                 disabled={!enabled}
-                onClick={() => preset(presetValue)}
-                className="app-button px-4 text-[12px] disabled:opacity-50"
+                onClick={applyCustomPreset}
+                className="app-icon-button h-6 w-6 disabled:opacity-50"
+                title="Add quick preset"
+                aria-label="Add quick preset"
               >
-                {presetValue} MB/s
+                <Plus size={14} />
               </button>
-            ))}
+            </div>
           </div>
         </section>
       </div>