v1.9.0 — Claude Chat page, per-user cache efficiency, mobile support

A new Claude Chat page, per-user cache efficiency everywhere, richer Users columns, a Claude Code per-user table — and the whole dashboard now works on mobile. (Deployed to production 2026-07-12.)

Added

• Claude Chat page (new sidebar menu, 19th route): period usage & activity for claude.ai conversations — active users, messages (incl. extended-thinking), conversations, artifacts, projects, skill/connector uses, web searches; two daily-trend charts and a sortable per-user table. Fully group-scoped.
• Per-user Cache Efficiency: a Cache Efficiency card in the user detail panel (hit rate + cache read/write/uncached tiers) and a sortable Cache Hit column in the Users table — window-aligned with the engagement columns.
• Users table surface columns: Cowork (sessions + actions) and Design (sessions).
• Claude Code per-user table: sessions / LOC / commits / PRs / accept rate, mirroring the Cowork/Design pattern.

Changed

• Mobile support: hamburger drawer navigation (a11y-safe: closed drawer leaves the tab order; Escape/backdrop/nav-tap close), stacked KPI grids and chart pairs, horizontally scrolling tables, tightened padding. Verified at 375px with zero horizontal overflow.

Fixed

• Desktop sidebar floating above the user-detail backdrop (flex-item z-index stacking-context leak → lg:z-auto).
• Save-as-PDF layouts preserved via print: grid fallbacks (lg: classes don't apply on A4 portrait).
• FloatingChat overlap with the open drawer; chat get_cost_summary stays org-wide.

Full changelog: https://github.com/whchoi98/claude-code-dashboard/blob/main/CHANGELOG.md