feat: right-click menus everywhere, workspace/session cost, long-term DB safety

Right-click menus: one portal shell (components/ContextMenu.tsx) for every
item with actions - sidebar/Recents/archived session rows (SessionMenu),
console tabs, pane headers, the Changes panel's files/tree/commits, the
workspace home, sessions outside a workspace (SessionRowMenu: Sessions
table, Dashboard, Activity, Workflow runs), prompt images, every Settings
list and every Claude Code/Codex config list (FileItemMenu). Buttons stay;
a delete keeps its button's confirm; the shell stops portal clicks from
reaching the card that opened it.

Status bar: Workspace $ and Session $ on the Workspace page, from
?lane= on GET /api/pricing/cost and the focused/replayed session's cost.

Database, no data dropped: synchronous=NORMAL, journal_size_limit 64 MB,
hourly PASSIVE checkpoint + PRAGMA optimize, idx_events_session_created
(replacing the redundant idx_events_session), watchdog reads
sessions.transcript_path, transcript parsed before the hook's write
transaction, GET /api/sessions/:id?events=0 for the web page (reloads only
on its own session, debounced), streamed export, transactional clear-data
and chunked cleanup, subagent import reads tool_use_ids once, runtime logs
rotated past 5 MB.

client/src/pages/Sessions.tsx

@@ -1,6 +1,6 @@
 /**
  * @file Sessions.tsx
- * @description Displays a list of all recorded sessions with filtering, searching, and pagination features. Sessions are updated in real-time based on events received from the event bus.
+ * @description Displays a list of all recorded sessions with filtering, searching, and pagination features; a row's right-click opens `SessionRowMenu`. Sessions are updated in real-time based on events received from the event bus.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 /* =============================================================================
@@ -75,6 +75,8 @@ import { SessionStatusBadge } from "../components/StatusBadge";
 import { SessionToolBadge } from "../components/SessionToolBadge";
 import { EmptyState } from "../components/EmptyState";
 import { TableRowSkeleton } from "../components/Skeleton";
+import { useContextMenu } from "../components/ContextMenu";
+import { SessionRowMenu } from "../components/SessionRowMenu";
 import { formatDateTime, formatDuration, truncate, fmtCost } from "../lib/format";
 import {
   effectiveSessionStatus,
@@ -87,6 +89,7 @@ const PAGE_SIZE = 10;
 
 export function Sessions() {
   const navigate = useNavigate();
+  const rowCtx = useContextMenu<Session>();
   const { t } = useTranslation("sessions");
   const [sessions, setSessions] = useState<Session[]>([]);
   const [total, setTotal] = useState(0);
@@ -271,6 +274,14 @@ export function Sessions() {
 
   return (
     <div className="animate-fade-in">
+      {rowCtx.menu && (
+        <SessionRowMenu
+          session={rowCtx.menu.item}
+          x={rowCtx.menu.x}
+          y={rowCtx.menu.y}
+          onClose={rowCtx.close}
+        />
+      )}
       <div className="flex flex-wrap items-center justify-between gap-3 mb-8">
         <div className="flex items-center gap-3">
           <div className="w-9 h-9 rounded-xl bg-accent/15 flex items-center justify-center">
@@ -427,6 +438,7 @@ export function Sessions() {
                   <tr
                     key={session.id}
                     onClick={() => navigate(`/sessions/${session.id}`)}
+                    onContextMenu={(e) => rowCtx.open(e, session)}
                     className="hover:bg-surface-4 transition-colors cursor-pointer group"
                   >
                     <td className="px-5 py-4">