Closes #142

Summary

• Moves spend/time metrics directly under the overview hero so total cost, total tokens, elapsed time, P95 latency, top agent, and top model become the first hierarchy.
• Replaces the single triage card with an Inspect First panel covering top cost, slowest, and critical sessions.
• Keeps shortcut hints visible while moving them below the primary spend/time strip.

User value

Users can understand historical spend and immediately jump into the sessions most likely to explain slow or expensive agent work from the first overview screen.

Scope

• TUI overview layout and ordering only.
• English/Chinese labels for the new overview metrics and Inspect First rows.
• Regression tests for spend/time hierarchy, Inspect First content, and translated compact/runtime labels.

Changed files

• internal/tui/tui.go
• internal/tui/tui_test.go
• internal/i18n/i18n.go

Test plan

• go test ./internal/tui
• go test ./...
• go build -o /tmp/agenttrace-parser-check ./cmd/agenttrace
• /tmp/agenttrace-parser-check --doctor || true
• /tmp/agenttrace-parser-check --demo --overview -f json
• go test ./internal/tui -run 'TestOverview(PrioritizesSpendTimeMetrics|ShowsInspectFirstPanel)' -count=1 -v

Fixture/privacy note

No real user session data, prompts, logs, tokens, or secrets were added. Tests use existing synthetic in-memory TUI fixtures. Local doctor validation saw 4264 session files, but no local session content was committed.

Risk

Medium-low. This changes TUI visible hierarchy and overview panel ordering. Parser behavior, source compatibility, CLI behavior, and JSON/Markdown/HTML report contracts are unchanged.

Non-goals

• No parser/source changes.
• No report contract changes.
• No README/docs asset changes.
• No release, package, install, or launch-kit changes.

Blackboard events

• Claimed [TUI] Rework overview around spend, tokens, time, and slow-run triage #142 with: Parser & Implementation Agent is taking this.
• Created and pushed branch parser/142-overview-spend-time-triage.
• Implemented overview spend/time hierarchy and Inspect First triage panel.
• Terminal capture evidence: focused overview tests passed with -v; doctor confirmed a large local history scan surface with 4264 session files.

Release impact

patch; affects TUI visible behavior only. Parser/source compatibility: no. CLI behavior: no. JSON/Markdown/HTML report contract: no. Install/package docs: no.

Handoff suggestion: Growth

Suggested release note: Overview now leads with spend/time metrics and an Inspect First section for top-cost, slowest, and critical sessions.