feat: replace input panel with ink-text-input component

[avoidwork]

What

Replace the current custom InputPanel component with ink-text-input to gain built-in keyboard handling, cursor navigation, focus management, and multi-line support without manual implementation.

Changes

• src/tui/inputPanel.js — Replaced Blink component with ink-text-input wrapper. New API: value, onChange, onSubmit, onFocus, onBlur, focus props
• src/tui/app.js — Updated InputPanel usage to use new API. Input state now managed by ink-text-input component via onChange callback
• tests/unit/tui.test.js — Replaced Blink tests with InputPanel tests
• package.json — Added ink-text-input@^6.0.0 dependency

Why

The current InputPanel is purely presentational — all input handling lives in App's single useInput hook (~75 lines). This approach works but requires manual implementation of every keyboard feature.

Three specific gaps:

• Better UX — cursor movement, word deletion (Ctrl+W), line clearing (Ctrl+U), text selection are not implemented
• Less code in App — input logic is scattered across the App component and should be encapsulated
• Multi-line input — the current approach would need more work; ink-text-input handles this natively

OpenSpec

Change: replace-input-panel-ink-text-input

• Proposal: openspec/changes/replace-input-panel-ink-text-input/proposal.md
• Design: openspec/changes/replace-input-panel-ink-text-input/design.md
• Tasks: openspec/changes/replace-input-panel-ink-text-input/tasks.md
• Specs: specs/input-cursor/spec.md, specs/tui-interface/spec.md

Testing

• Unit tests pass (1043 tests)
• Lint passes (oxlint + oxfmt)
• Coverage maintained
• Application starts without crashing

Fixes #591

[avoidwork]

Audit Results: Issue #591 → PR #592

Goal Fulfillment

• Replace InputPanel with ink-text-input — Done. Blink component removed, replaced with ink-text-input wrapper
• Add ink-text-input dependency — Done. Added ink-text-input@^6.0.0 to package.json
• Move input handling from App's useInput hook — Done. Input state now managed by component via onChange callback
• Wire callbacks back to App — Done. onSubmit → handleSubmit, onChange → setInputText, onFocus/onBlur → setInputFocused
• Preserve history navigation — Done. Up/down arrow handling kept in App's useInput hook
• Preserve onboarding input flow — Done. Separate useInput path for onboarding unchanged
• Preserve streaming state awareness — Done. No changes to streaming/interrupt handling

Spec Compliance

• input-cursor spec: Modified — cursor rendering now delegated to ink-text-input. All scenarios still valid.
• tui-interface spec: Modified — keyboard navigation updated to reflect ink-text-input's built-in handling. Tab key handling for focus toggle preserved in App.

Task Completion

All 14 tasks in tasks.md completed:

• Setup: dependency added and installed
• Component replacement: Blink removed, ink-text-input wrapper created with proper API
• App updates: InputPanel usage updated, useInput hook simplified
• Tests: Blink tests replaced with InputPanel tests
• Verification: All 1043 tests pass, lint passes, app starts cleanly

Quality Check

• No obvious issues found
• Code follows existing patterns (React.createElement, JSDoc comments)
• No hardcoded secrets or credentials
• No breaking changes to public APIs (InputPanel props changed but this is internal)
• Tests updated to match new component API

Deviations from Plan

• None. Implementation matches the proposal and design documents exactly.