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/Dashboard.tsx

@@ -1,6 +1,6 @@
 /**
  * @file Dashboard.tsx
- * @description Main dashboard page showing real-time stats, active agents, recent activity feed, an Analytics tab, and a System Health tab for Claude Code sessions.
+ * @description Main dashboard page showing real-time stats, active agents, recent activity feed, an Analytics tab, and a System Health tab for Claude Code sessions; a recent event's right-click opens its session's `SessionRowMenu`.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 /* =============================================================================
@@ -96,6 +96,8 @@ import { isRemoteDataRefreshMessage } from "../lib/remoteDataEvents";
 import { useDataScope } from "../lib/dataScope";
 import { StatCard } from "../components/StatCard";
 import { AgentCard } from "../components/AgentCard";
+import { useContextMenu } from "../components/ContextMenu";
+import { SessionRowMenu } from "../components/SessionRowMenu";
 import { AgentStatusBadge } from "../components/StatusBadge";
 import { EmptyState } from "../components/EmptyState";
 import { Tip } from "../components/Tip";
@@ -2358,6 +2360,7 @@ function SystemHealthTab() {
 export function Dashboard() {
   const navigate = useNavigate();
   const { t } = useTranslation("dashboard");
+  const eventCtx = useContextMenu<string>();
 
   // Persistent Tab State
   const [tabParams] = useSearchParams();
@@ -2865,11 +2868,20 @@ export function Dashboard() {
                 />
               ) : (
                 <div className="card divide-y divide-border">
+                  {eventCtx.menu && (
+                    <SessionRowMenu
+                      session={{ id: eventCtx.menu.item }}
+                      x={eventCtx.menu.x}
+                      y={eventCtx.menu.y}
+                      onClose={eventCtx.close}
+                    />
+                  )}
                   {recentEvents.slice(0, visibleActivityCount).map((event, i) => (
                     <div
                       key={event.id ?? i}
                       className="px-4 py-3 flex items-center gap-3 hover:bg-surface-4 transition-colors cursor-pointer"
                       onClick={() => navigate(`/sessions/${event.session_id}`)}
+                      onContextMenu={(e) => eventCtx.open(e, event.session_id)}
                     >
                       <AgentStatusBadge
                         status={