memory: log per-session token tracking (done, pending Windows verify)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

memory.md

@@ -56,7 +56,7 @@ Durable memory for this project. Read at session start, update before session en
 Four-agent research pass (terminal-landscape, AI-orchestration, xterm/Tauri ecosystem, codebase gap-analysis) into things to add. **Headline finding:** tiletopia already owns the hard primitives (tiling, multi-window, broadcast, MCP control surface); the real gap vs Conductor/Crystal/claude-squad/Vibe-Kanban is *git-worktree isolation + per-session status/cost/diff visibility*. Full agent deliverables are in this session's conversation; condensed here.
 
 **→ Exploring first (user-selected 2026-05-28):**
-- [ ] **Per-session cost / token tracking.** Parse `~/.claude/projects/<project>/<session>.jsonl` (`message.usage`: input/output/cache_read/cache_write + model per assistant line) → tokens + estimated $ per pane and per workspace. Easy parsing; the fiddly bit is mapping a tiletopia pane → its session file (capture session id / cwd at spawn). Difficulty: easy–medium.
+- [x] ~~**Per-session cost / token tracking.**~~ Done (code) 2026-05-28 — **WSL-only v1, pending Windows runtime verify.** Backend `src-tauri/src/usage.rs` (`get_claude_usage(distros)` command): probes `$HOME` per distro via `wsl.exe`, reads `~/.claude/projects/*/*.jsonl` over the `\\wsl.localhost\<distro>` UNC share, tallies `message.usage` **per model per assistant line** (sessions can switch models). Cached by `(path,size,mtime)`; recency-capped 30d/50 sessions. Frontend: `src/lib/usage.ts` holds the editable pricing table (per-MTok, matched by opus/sonnet/haiku substring) + cost/format helpers; `UsagePanel.tsx` (MCP-panel modal pattern) lists sessions, highlights those whose transcript `cwd` matches an open pane (`[pane: label]`); titlebar 💰 total chip; App polls 20s (visible) / 5s (panel open); **Ctrl+Shift+U** opens it. **Design choice:** session-list attribution (not 1:1 pane binding) — avoids the unsolvable "2 claudes in one cwd" ambiguity. **Caveats:** cost is an estimate (cache-creation priced at 5m rate; rates hardcoded, may drift); panes with no explicit cwd (`~`) won't highlight; PowerShell/SSH show nothing. Plan: `~/.claude/plans/greedy-cooking-flask.md`.
 - [ ] **Smart link providers.** `terminal.registerLinkProvider()` to make file paths (`src/foo.ts:12:3`), `localhost:PORT`, and error locations clickable — more flexible than the regex-only web-links addon already loaded. Open file in editor / browser. Difficulty: medium.
 - [x] ~~**Find in scrollback.**~~ Done + **verified on Windows 2026-05-28** — `@xterm/addon-search` + new `src/components/SearchBar.tsx`/`.css` overlay, Ctrl+Shift+F open / Enter / Shift+Enter / Esc, regex + case toggles, decoration highlight.
 - [x] ~~**Unicode 11 + grapheme width.**~~ Done + **verified on Windows 2026-05-28** — `@xterm/addon-unicode11` loaded after CanvasAddon, `term.unicode.activeVersion = '11'`. (Skipped the separate `addon-unicode-graphemes` for now.)