fix(dashboard): extract remaining 158 hardcoded aria-labels to i18n

[OneStepAt4time]

Description

Follow-up to #3194 (which fixed 16 aria-labels in 3 pages). Full UAT scan reveals 158 hardcoded aria-labels across the entire dashboard codebase. Screen readers in non-English locales still hear English for all of these.

Scope by File (top 15)

File	Count
components/overview/SessionTable.tsx	12
components/session/PauseControlBar.tsx	11
components/session/DriverControlBar.tsx	9
pages/AuditPage.tsx	8
components/Layout.tsx	7
components/session/AcpApprovalModal.tsx	6
components/analytics/RateLimitChart.tsx	5
components/ToastContainer.tsx	4
components/session/TerminalDebugTab.tsx	4
components/session/OperatorTimeline.tsx	4
components/session/AcpChatView.tsx	4
components/routines/CalendarGrid.tsx	4
pages/SessionsPage.tsx	3
pages/OverviewPage.tsx	3
pages/MetricsPage.tsx	3
+ ~30 more files	~75

Additional UAT Findings

Hardcoded hex colors (5 instances)

These should use CSS variables:

• text-[#666] in MetricCard.tsx (2x), MetricsPanel.tsx (1x)
• text-[#ccc] in TokenBreakdown.tsx (1x)
• hover:border-[#333] in ConfirmDialog.tsx, SaveTemplateModal.tsx

Pages without test files

• ActivityPage.tsx (49L)
• AnalyticsPage.tsx (539L)
• CostPage.tsx (408L)
• UsersPage.tsx (17L)

Acceptance Criteria

• All 158 aria-label attributes use t() calls
• Translation keys added to both en.ts and it.ts
• 5 hardcoded hex colors replaced with CSS variables
• No regressions in existing tests (1265+)

Priority Justification

P3 — a11y gap but not blocking functionality. Should be addressed incrementally (batch by component).

— Daedalus 🏛️

[OneStepAt4time]

Implementation Plan — Batched PRs

This is too large for a single PR (158 strings, 60 files). Proposing 6 batches:

Batch 1: Shared components (~25 strings) — Layout, Breadcrumb, ToastContainer, shared/*
Batch 2: Session controls (~35 strings) — DriverControlBar, PauseControlBar, AcpSessionShell, AcpApprovalModal, AcpChatView, SessionHeader
Batch 3: Session content (~30 strings) — Timeline, Terminal, Diff, Audit trail components
Batch 4: SessionTable + Overview (~12 strings) — SessionTable, VirtualizedSessionList
Batch 5: Analytics, Cost, Calendar (~20 strings) — analytics/, cost/, routines/*
Batch 6: Pages (~25 strings) — AuditPage, MetricsPage, OverviewPage, PipelinesPage, etc.

Also fix: 5 hardcoded hex colors → CSS vars

— Daedalus 🏛️