feat(ui): redesign the overview page as a trend-first command deck

Replace the ten-small-cards overview with an action bar, four vitals
tiles carrying 72-sample sparklines seeded from /server/history, a
two-series throughput chart, a TCP/UDP connections chart, and a
grouped system strip (uptime xray|os, panel ram|threads, ip
addresses). StatusCard and XrayStatusCard are deleted; every modal
stays reachable from the action bar, the Xray error message moves
into a tooltip on the state pill, and the panel version text keeps
opening the update modal (the dev-channel switch lives there) even
when no update is available. Live values sit beside the
upload/download and tcp/udp legends, a health sentence appears only
when a vital crosses the shared warn/crit thresholds now exported
from models/status, and load average is left to System History.

The sidebar becomes an auto-collapsed 72px icon rail that expands as
an overlay on hover: rail width, brand-row height and menu paddings
are pinned so nothing shifts during the transition, the collapsed-menu
tooltips are disabled, hover state survives the per-page sidebar
remounts (with a matches(':hover') resync), and the manual collapse
trigger is gone.

Sparkline gains rgb()/rgba() support in its fill gradient, a
showLegend prop so pages stop reaching into its internals, and loses
a dependency-less repaint effect that doubled canvas paints. Chart
tooltips show clock time via the new TimeFormatter.formatClock;
accents come from theme tokens instead of status.cpu.color. Verified
by screenshot at 390/800/1150/1280/1400/1600px in light and dark,
en and fa-IR, plus programmatic geometry checks on the sidebar.
Locale files gain 8 keys and lose 9 dead ones across all 13
languages.

internal/web/translation/en-US.json

@@ -107,7 +107,6 @@
     "routing": "Routing",
     "outbounds": "Outbounds",
     "apiDocs": "API Docs",
-    "link": "Manage",
     "donate": "Donate",
     "docs": "Documentation",
     "openMenu": "Open menu"
@@ -127,12 +126,9 @@
     },
     "index": {
       "cpu": "CPU",
-      "logicalProcessors": "Logical Processors",
-      "frequency": "Frequency",
       "swap": "Swap",
       "storage": "Storage",
       "memory": "RAM",
-      "threads": "Threads",
       "xrayStatus": "Xray",
       "stopXray": "Stop",
       "restartXray": "Restart",
@@ -153,7 +149,6 @@
       "xrayStatusRunning": "Running",
       "xrayStatusStop": "Stopped",
       "xrayStatusError": "Error",
-      "operationHours": "Uptime",
       "systemHistoryTitle": "System History",
       "historyTitleCpu": "CPU Usage",
       "historyTitleMem": "Memory Usage",
@@ -171,7 +166,6 @@
       "historyTabLoad": "Load",
       "historyTabConnections": "Connections",
       "historyTabDiskUsage": "Disk Usage",
-      "charts": "Charts",
       "xrayMetricsTitle": "Xray Metrics",
       "xrayTitleHeap": "Allocated Heap Memory",
       "xrayTitleSys": "Memory Reserved from OS",
@@ -200,7 +194,6 @@
       "overallSpeed": "Overall Speed",
       "upload": "Upload",
       "download": "Download",
-      "totalData": "Total Data",
       "sent": "Sent",
       "received": "Received",
       "xraySwitchVersionDialog": "Do you really want to change the Xray version?",
@@ -250,7 +243,18 @@
       "exportDatabasePgDesc": "Click to download a PostgreSQL dump (.dump) of your current database to your device.",
       "importDatabasePgDesc": "Click to select and upload a PostgreSQL backup (.dump), a SQLite database (.db), or a SQLite migration dump to restore your database. This replaces all current data.",
       "migrationDownload": "Download Migration",
-      "migrationDownloadPgDesc": "Click to download a .db SQLite database built from your PostgreSQL data, ready to run this panel on SQLite."
+      "migrationDownloadPgDesc": "Click to download a .db SQLite database built from your PostgreSQL data, ready to run this panel on SQLite.",
+      "avg": "avg",
+      "peak": "peak",
+      "free": "free",
+      "openSockets": "open sockets",
+      "throughputSub": "Interface total",
+      "avgWindow": "Avg over window",
+      "healthWarm": "{list} — running warm",
+      "healthCritical": "{list} — critical",
+      "panel": "Panel",
+      "threads": "Threads",
+      "uptime": "Uptime"
     },
     "inbounds": {
       "totalDownUp": "Total Sent/Received",