fix(frontend): stabilize speed tags on inbound and client pages (#5930)

* fix(frontend): add shared stable speed-tag style

Give live up/down rate tags a fixed width, centered layout, nowrap,
and tabular numerals so digit/unit changes cannot reflow the Speed column.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* fix(frontend): stabilize InboundSpeedTag and ClientSpeedTag layout

Apply the shared speed-tag class/style to both live rate tags and lock
the behavior with a focused component test for small and large rates.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* fix(frontend): align speed columns with stable tag width

Widen inbound/client Speed columns to match the fixed tag and apply the
same stable style to idle dash cells so active/idle swaps do not jitter.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* fix(frontend): scope stable speed tags to table cells and fit content

---------

Co-authored-by: x06579 <x06579@ai-dashboard>
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/components/clients/ClientSpeedTag.tsx

@@ -2,6 +2,7 @@ import { Tag } from 'antd';
 
 import { SizeFormatter } from '@/utils';
 import type { ClientSpeedEntry } from '@/hooks/useClients';
+import { SPEED_TAG_CLASS_NAME, SPEED_TAG_STYLE } from '@/components/utility/speedTagStyle';
 
 export type { ClientSpeedEntry };
 
@@ -11,11 +12,16 @@ export function isActiveSpeed(speed?: ClientSpeedEntry): speed is ClientSpeedEnt
 
 interface ClientSpeedTagProps {
   speed: ClientSpeedEntry;
+  tableCell?: boolean;
 }
 
-export function ClientSpeedTag({ speed }: ClientSpeedTagProps) {
+export function ClientSpeedTag({ speed, tableCell = false }: ClientSpeedTagProps) {
   return (
-    <Tag color="blue">
+    <Tag
+      color="blue"
+      className={tableCell ? SPEED_TAG_CLASS_NAME : undefined}
+      style={tableCell ? SPEED_TAG_STYLE : undefined}
+    >
       ↑ {SizeFormatter.speedFormat(speed.up)}
       {' / '}
       ↓ {SizeFormatter.speedFormat(speed.down)}

frontend/src/components/utility/speedTagStyle.ts

@@ -0,0 +1,21 @@
+import type { CSSProperties } from 'react';
+
+export const SPEED_TAG_CLASS_NAME = 'table-speed-tag' as const;
+export const SPEED_TAG_WIDTH = 200 as const;
+export const SPEED_TABLE_CELL_INLINE_PADDING = 8 as const;
+
+export const SPEED_TAG_STYLE = {
+  width: SPEED_TAG_WIDTH,
+  display: 'inline-flex',
+  alignItems: 'center',
+  justifyContent: 'center',
+  textAlign: 'center',
+  whiteSpace: 'nowrap',
+  fontVariantNumeric: 'tabular-nums',
+  marginInlineEnd: 0,
+  boxSizing: 'border-box',
+  overflow: 'hidden',
+  textOverflow: 'ellipsis',
+} as const satisfies CSSProperties;
+
+export const SPEED_COLUMN_WIDTH = SPEED_TAG_WIDTH + SPEED_TABLE_CELL_INLINE_PADDING * 2;