[idunara21]

Summary

Usability improvements for moving around long chats and managing the sidebar. Split into two commits so they can be reviewed (or reverted) independently.

1. Chat navigation (feat(chat))

• Scroll to end pill: appears centered at the bottom once you scroll away from the latest message. Clicking it jumps to the end and re-pins the transcript so streaming output is followed again.
• "New messages" hint: if the agent produces output while you are reading further up, the pill turns into "New messages" with a dot instead of yanking the view down.
• Prompt rail: a slim minimap on the left edge with one line per user prompt. The prompt you are currently reading is highlighted. Hovering a line shows a card with the prompt and the beginning of the reply; clicking jumps there. Shown only when there are 2+ prompts; the transcript gets a little extra left padding then so the rail never covers text.
• Keyboard: Alt+↑ / Alt+↓ step between prompts, Alt+End jumps to the end.

Implementation notes:

• usePinnedScroll gains scrollToBottom(); jumps re-align on the next frame because rows use content-visibility: auto and heights settle after scrolling.
• Rows carry data-transcript-role / data-message-id so navigation works on the rendered DOM; prompt previews come from a pure buildPromptMarkers(rows) (unit-tested).
• The DOM structure the existing viewport tests rely on is unchanged; the rail lives in a wrapper outside the scroll container.

2. Sidebar (feat(sidebar))

• Fully hide instead of collapsing to an icon strip (collapsible="offcanvas"). The toggle now sits next to the logo in the sidebar header; the title-bar toggle only shows while the sidebar is hidden (or in the mobile drawer layout). Ctrl+B still works.
• Fix: AppSidebar passed className="relative", which overrode the container's fixed positioning. With icon collapsing this went unnoticed, but with offcanvas it kept the sidebar's space reserved after hiding.
• Drag to resize: the inner edge of the sidebar is a resize handle (200–480 px, default 256 px, persisted via a new sidebarWidth setting). Double-click resets. The handle is a focusable role="separator" with arrow keys and Home/End support. Width updates live via the CSS variable during drag and is persisted once on release; transitions are disabled while dragging.
• Logo is left-aligned next to the toggle so it stays in place while resizing.

All new strings are added to en, de and es.

Testing

• vp check passes (format, lint, types)
• vp test: all suites pass, including new tests for the navigation pill, Alt+End, prompt markers, the prompt rail, and sidebar resizing (keyboard, reset, clamping)
• Manually checked in the web dev build: hide/show sidebar, main area reclaims full width, logo placement

Notes / open questions

• The icon-collapsed sidebar mode (and CollapsedProjectPopover) is no longer reachable from AppSidebar. I left that code untouched to keep the diff focused; happy to remove it, or to keep icon mode as an option if you prefer.

🤖 Generated with Claude Code

[touch2be]

Superseded by #167 (same commits, opened from a branch in this repo).