Show full tool input on tool call cards, split from output #35

Part of #2.

Tool call cards today show a one-line summary and the raw output. The full input is lost in src/renderer/timeline.ts: toolArgsSummary truncates unknown tools to 120 characters and drops edit old/new text entirely, so a user expanding a card cannot inspect what the tool was actually asked to do.

Slice:

• Keep the full formatted tool input on the tool entry, for both archived messages (entriesFromMessages) and live events (tool_execution_start).
• Format per tool: bash shows the command, read/write/edit show the path plus content or old/new text where present, other tools show pretty-printed arguments with no truncation.
• Render Input and Output as separate labelled sections inside the expanded card. Keep the existing header summary, running/done/failed state, and collapsed-by-default behaviour.

Out of scope: diff rendering for edit/write, copy buttons, and output truncation controls. Those are follow-up slices on #2.

Acceptance:

• Unit tests cover full input formatting, including an edit call whose old/new text survives and a long argument value that is not truncated.
• An integration test renders an expanded card and checks the Input and Output sections are distinct.
• Existing unit, integration, lint, typecheck, and build gates pass.