Summary

Two related UX improvements to the toolpath-desktop Browse screens:

1. Sort by recency. Claude projects/sessions, Pi projects/sessions, and Git branches previously rendered in backend-emission order — usually alphabetical or directory-walk. Now they're sorted most-recently-active first, matching the convention the tray popover's Recent list already uses (src/tray.rs:87).

2. Label Claude projects with their latest session title. Project rows previously showed the directory basename, which is uninformative for worktrees (2f297b, fa7bdc, c44db4…). Now each project row displays the first-user-message of its most-recent session as the primary title, falling back to the basename while the title loads.

What changed

Backend (crates/toolpath-desktop/src/commands/sources.rs, main.rs)

• ClaudeProjectQuick gains last_activity: Option<String>, populated by a new newest_jsonl_mtime helper — a cheap directory stat walk (max mtime across the project's .jsonl files), no JSONL parsing. Preserves the original perf intent of the streaming payload.
• New IPC command claude_project_latest_title(project_path) reads the most-recent session's first user message (via existing ClaudeConvo::title) and returns Option<String>. Registered in the Tauri invoke handler.

Frontend (frontend/src/lib/)

• byRecencyDesc comparator in update.ts — descending, nulls last, lexicographic on RFC3339.
• Sort on arrival for every stream handler: ClaudeProjectReceived, ClaudeSessionReceived, PiProjectReceived, PiSessionReceived, GitBranchesLoaded.
• PiSlice.maxTimestampByProject: Record<string, string> — Pi has no project-level timestamp, so project-list recency is derived frontend-side from streamed session timestamps.
• ClaudeSlice.projectTitles: Record<string, string> + ClaudeProjectTitleLoaded msg; ClaudeProjectReceived now kicks off the title fetch lazily so project rows paint immediately and titles fill in after.
• BrowseClaude.svelte renders projectTitles[p.project_path] ?? p.display_name.

Design notes for reviewers

• The streaming ClaudeProjectQuick payload previously documented last_activity as "deliberately omitted to avoid re-introducing per-session metadata reads." The new stat-based approach respects that intent — we only stat files (no JSON parsing) to get recency. The expensive title read is split into a separate lazy command.
• Pi project recency uses the frontend-computed max of streamed session timestamps. Projects without sessions yet sit at the bottom until their first session streams in and re-sorts the list. Chosen over adding a backend field to keep the change surface small.
• Git branches are auto-selected by sortedList[0].name — unchanged semantically from "first in display order is selected" but now "first" means "most recent".

Test plan

• cargo build -p toolpath-desktop — clean
• cargo test -p toolpath-desktop — 17/17 pass
• bun run check in frontend — 0 errors, 0 warnings, 170 files
• bun run build — 194 modules transformed, clean
• cargo tauri dev — manual verification:
  • Browse → Claude Code: projects ordered most-recently-active first; worktree project rows show a conversation title instead of 2f297b-style basenames; expanded sessions ordered newest-first.
  • Browse → pi.dev: sessions within each project newest-first; after sessions stream in, projects reorder so the ones with the newest session float to the top.
  • Browse → Local git: load a repo with multiple branches; branches ordered by tip-commit timestamp desc; newest branch auto-selected.
  • Compare tray popover's Recent list with Browse lists — same provider's top row should match.