chore: drop redundant background repaints so surfaces inherit their parent (#27576)

* chore: drop redundant background repaints so surfaces inherit their parent

Four spots repaint the exact color their parent surface already provides
(bg-white / dark:bg-gray-900 rows inside same-colored pages and modals,
and the selectClass dark repaint inside the connection modals — the
sibling input const is already fully transparent). Visually identical in
stock light and dark; removing them lets instance theming show through
instead of leaving opaque boxes:

- .tiptap tr (app.css) — table rows in notes/editors
- Edit User Group Users tab body rows (common Modal surface)
- AddToolServerModal + AddTerminalServerModal selectClass dark repaint

The matching repaints inside the ModelUsage/UserUsage components are
not part of this change — those files were dead code and were removed
entirely in #27574.

* chore: catch remaining redundant surface repaints missed in the first pass

Same rule as the previous commit — every one of these repaints the exact
color its parent surface already provides, so removal is stock-identical
in light and dark while letting instance theming show through:

- Analytics Dashboard's inline Model Usage / User Activity row markup
  (the Analytics tab renders these tables from Dashboard.svelte itself;
  the unreferenced ModelUsage/UserUsage component files were removed
  in #27574)
- Evaluations Feedbacks + Leaderboard body rows (settings modal surface)
- admin UserList body rows (app page surface)
- chat markdown tables (MarkdownTokens): thead and body rows — unlike
  the tiptap header (gray-850 contrast, untouched), this thead painted
  the page's own color
- CitationsModal source rows (common Modal surface)
- AddConnectionModal selectClass dark repaint — third copy of the same
  const already fixed in AddToolServerModal / AddTerminalServerModal

src/app.css

@@ -685,7 +685,7 @@ html.high-contrast.dark .ProseMirror p.is-editor-empty:first-child::before {
 }
 
 .tiptap tr {
-	@apply bg-white dark:bg-gray-900 dark:border-gray-850 text-xs;
+	@apply dark:border-gray-850 text-xs;
 }
 
 .tippy-box[data-theme~='transparent'] {

src/lib/components/AddConnectionModal.svelte

@@ -63,7 +63,7 @@
 	const inputClass =
 		'bg-transparent outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 	const selectClass =
-		'dark:bg-gray-900 bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
+		'bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 
 	const parsePassthroughParams = (value: string) =>
 		value

src/lib/components/AddTerminalServerModal.svelte

@@ -62,7 +62,7 @@
 	const inputClass =
 		'bg-transparent outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 	const selectClass =
-		'dark:bg-gray-900 bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
+		'bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 
 	const stringifyJson = (value: object | null | undefined) => {
 		return JSON.stringify(value && Object.keys(value).length ? value : {}, null, 2);

src/lib/components/AddToolServerModal.svelte

@@ -72,7 +72,7 @@
 	const inputClass =
 		'bg-transparent outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 	const selectClass =
-		'dark:bg-gray-900 bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
+		'bg-transparent pr-5 outline-hidden placeholder:text-gray-300 dark:placeholder:text-gray-700';
 
 	const registerOAuthClientHandler = async () => {
 		if (url === '') {

src/lib/components/admin/Analytics/Dashboard.svelte

@@ -468,7 +468,7 @@
 					<tbody>
 						{#each sortedModels as model, idx (model.model_id)}
 							<tr
-								class="bg-white dark:bg-gray-900 dark:border-gray-850 text-xs cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
+								class="dark:border-gray-850 text-xs cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
 								on:click={() => {
 									selectedModel = { id: model.model_id, name: model.name };
 									showModelModal = true;
@@ -581,7 +581,7 @@
 					</thead>
 					<tbody>
 						{#each sortedUsers as user, idx (user.user_id)}
-							<tr class="bg-white dark:bg-gray-900 dark:border-gray-850 text-xs">
+							<tr class="dark:border-gray-850 text-xs">
 								<td class="px-3 py-1 text-gray-400">{idx + 1}</td>
 								<td class="px-3 py-1 font-normal text-gray-900 dark:text-white">
 									<div class="flex items-center gap-2">

src/lib/components/admin/Evaluations/Feedbacks.svelte

@@ -418,7 +418,7 @@
 					<tbody class="">
 						{#each items as feedback (feedback.id)}
 							<tr
-								class="bg-white dark:bg-gray-900 dark:border-gray-850 text-xs cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-850/50 transition rounded-xl"
+								class="dark:border-gray-850 text-xs cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-850/50 transition rounded-xl"
 								on:click={() => openFeedbackModal(feedback)}
 							>
 								<td class=" py-0.5 text-right font-normal">

src/lib/components/admin/Evaluations/Leaderboard.svelte

@@ -201,7 +201,7 @@
 				<tbody>
 					{#each sortedModels as model, idx (model.id)}
 						<tr
-							class="bg-white dark:bg-gray-900 text-xs group cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-850/50 transition"
+							class="text-xs group cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-850/50 transition"
 							on:click={() => openModal(model)}
 						>
 							<td class="px-3 py-1.5 font-normal text-gray-900 dark:text-white">

src/lib/components/admin/Users/Groups/Users.svelte

@@ -234,7 +234,7 @@
 					</thead>
 					<tbody class="">
 						{#each users as user, userIdx (user?.id ?? userIdx)}
-							<tr class="bg-white dark:bg-gray-900 dark:border-gray-850 text-xs">
+							<tr class="dark:border-gray-850 text-xs">
 								<td class=" px-3 py-1 w-8">
 									<div class="flex w-full justify-center">
 										<Checkbox

src/lib/components/admin/Users/UserList.svelte

@@ -346,7 +346,7 @@
 			</thead>
 			<tbody class="">
 				{#each users as user (user.id)}
-					<tr class="bg-white dark:bg-gray-900 dark:border-gray-850 text-xs">
+					<tr class="dark:border-gray-850 text-xs">
 						<td class="px-3 py-1 font-normal text-gray-900 dark:text-white max-w-48">
 							<div class="flex items-center gap-2">
 								<ProfilePreview {user} side="right" align="center" sideOffset={6}>

src/lib/components/chat/Messages/Citations/CitationsModal.svelte

@@ -60,7 +60,7 @@
 				{#each citations as citation, idx}
 					<button
 						id={`source-${id}-${idx + 1}`}
-						class="no-toggle outline-hidden flex dark:text-gray-300 bg-white dark:bg-gray-900 rounded-xl gap-1.5 items-center"
+						class="no-toggle outline-hidden flex dark:text-gray-300 rounded-xl gap-1.5 items-center"
 						on:click={() => {
 							showCitationModal = true;
 							selectedCitation = citation;

src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte

@@ -193,9 +193,7 @@
 					class=" w-full text-sm text-start text-gray-500 dark:text-gray-400 max-w-full rounded-xl"
 					dir="auto"
 				>
-					<thead
+					<thead class="text-xs text-gray-700 uppercase dark:text-gray-400 border-none">
-						class="text-xs text-gray-700 uppercase bg-white dark:bg-gray-900 dark:text-gray-400 border-none"
-					>
 						<tr class="">
 							{#each token.header as header, headerIdx}
 								<th
@@ -220,7 +218,7 @@
 					</thead>
 					<tbody>
 						{#each token.rows as row, rowIdx}
-							<tr class="bg-white dark:bg-gray-900 text-xs">
+							<tr class="text-xs">
 								{#each row ?? [] as cell, cellIdx}
 									<td
 										class="px-3! py-2! text-gray-900 dark:text-white w-max {token.rows.length -