allozaur/feat/chat slash commands (#26716)

* base : slash-command/misc foundation - model icon and focus-selector constants

* feat : slash-command picker and command parsing helpers

* refactor : wire command and @-mention pickers into the chat form

* ui : improve model selector keyboard navigation and load/dismiss

* feat: Unify markdown/raw-text rendering under one setting with migration

* fix: Misc fixes - tool-call subtitle, assistant wrap, progress guards

* feat: Clamp and style numeric settings inputs from registry bounds

tools/ui/src/lib/components/app/settings/SettingsChat/SettingsChat.svelte

@@ -98,7 +98,12 @@
 				const numValue = Number(processedConfig[field]);
 				if (!isNaN(numValue)) {
 					if ((POSITIVE_INTEGER_FIELDS as readonly string[]).includes(field)) {
-						processedConfig[field] = Math.max(1, Math.round(numValue));
+						const entryByMinMax = SETTINGS_CHAT_SECTIONS.flatMap(
+							(section) => section.fields ?? []
+						).find((entry) => entry.key === field);
+						const lo = entryByMinMax?.min ?? 1;
+						const hi = entryByMinMax?.max ?? Number.POSITIVE_INFINITY;
+						processedConfig[field] = Math.max(lo, Math.min(hi, Math.round(numValue)));
 					} else {
 						processedConfig[field] = numValue;
 					}

tools/ui/src/lib/components/app/settings/SettingsChat/SettingsChatFields.svelte

@@ -83,12 +83,18 @@
 					<Input
 						id={field.key}
 						type={field.isPositiveInteger ? 'number' : 'text'}
-						{...field.isPositiveInteger ? { min: '1', step: '1' } : {}}
+						{...field.isPositiveInteger
+							? {
+									min: String(field.min ?? 1),
+									step: '1',
+									...(field.max != null ? { max: String(field.max) } : {})
+								}
+							: {}}
 						value={currentValue}
 						oninput={(e) => onConfigChange(field.key, e.currentTarget.value)}
 						placeholder={currentModelParams[field.key] != null
 							? `Default: ${normalizeFloatingPoint(currentModelParams[field.key])}`
-							: ''}
+							: (field.placeholder ?? '')}
 						class="w-full {isCustomRealTime ? 'pr-8' : ''}"
 					/>
 					{#if isCustomRealTime}