TUI Builder — Golden Rules + Quick Reference

Context gate: On first invocation in a session, run: touch /tmp/syllago-tui-builder-${PPID} This signals the tui-context-gate hook that the skill was loaded.

Golden Rules Checklist

Before any layout or component work, verify:

1. Mouse + keyboard parity on EVERY interactive element — zone.Mark() in View, zone.Get().InBounds() in updateMouse. No exceptions. If it responds to a keypress, it must respond to a click.
2. Subtract 2 from height for borders, 2 from width for borders
3. Never rely on auto-wrap — truncate explicitly (maxTextWidth = panelWidth - 4)
4. Use MaxWidth() not Width() — Width word-wraps
5. Use borderedPanel() for all bordered panels
6. Parent owns child sizes — call SetSize(), never let children calculate
7. All async work via tea.Cmd — never goroutines
8. All state changes returned from Update() — never mutate elsewhere
9. Always propagate Update() to active sub-models
10. Handle tea.WindowSizeMsg — store and recalculate

Component Message Contracts

Gotchas

• AdaptiveColor mutates renderer state. Fix: warmup render in TestMain().
• bubbletea v1 uses tea.KeyMsg, not tea.KeyPressMsg (v2 API). Check version before using spec code.
• Golden files with raw ANSI are fragile. Strip ANSI before storing.
• lipgloss.Width() is ANSI-aware, len() is not. Always use lipgloss.Width() for rendered strings.
• Children that never receive WindowSizeMsg render at zero size.
• goimports strips "unused" imports between edits. Add import and usage in a single Edit call.
• Cursor initialization with Reset(): When active = -1, Open() must default cursor to 0, not -1.
• lipgloss Width() wraps, MaxWidth() truncates. For bordered panels, always use both Width+MaxWidth and Height+MaxHeight. Without MaxHeight, content overflow pushes the header offscreen.
• Manual string splitting destroys zone markers. Never split rendered strings containing zone.Mark() on newlines or truncate by rune — the invisible zero-width markers get broken. Use lipgloss styling for dimension control instead.
• Sort indicators overflow short columns. "Files ▲" is 7 visual chars but the Files column is 5. Use headerCell() which truncates the label to make room for the indicator within the column width.
• App-level keys intercept search input. When the library search input is active, keys like 'a' (add), 'q' (quit), '1' (group switch) must be passed through to the search handler instead of triggering app shortcuts. Check table.searching before handling global letter keys.
• Help bar separator is middle dot (·) not asterisk (*). Cleaner look.
• Metadata bar steals table height. When adding a fixed-height panel below a variable-height component (like table + metadata bar), always reduce the variable component's height in both SetSize() AND View(). If only one is updated, the table renders at the wrong height on resize vs initial draw.
• Modal lipgloss.Place() centering. Use lipgloss.Place(width, height, lipgloss.Center, lipgloss.Center, rendered) for modal centering — not manual padding math. Handles terminal resize automatically.
• YAML folded scalars add trailing newlines. Descriptions from loadout.yaml using > have \n at the end. Always sanitize catalog text fields before rendering in the TUI.
• Unified frame requires manual border construction. borderedPanel() can't create shared borders between sections. Build frames manually: ╭/╰ for corners, ├──┤ for internal separators, ├──┬──┤/╰──┴──╯ for split pane junctions.
• Metadata panel height is constant (metaBarLines=3 + 1 separator). Type-specific line 3 is blank for simple types, not omitted. This prevents the frame from shifting when scrolling between hooks and skills.
• Explorer needs providers for metadata. Pass providers + repoRoot to newExplorerModel() so it can compute installed status via computeMetaPanelData().
• Keyboard-only components are bugs. If a View renders interactive elements without zone.Mark(), mouse users can't interact with them. Every radio option, checkbox row, list item, button, and text input needs a zone mark in View and a corresponding zone.Get().InBounds() check in updateMouse. The checkboxList component automates this via zonePrefix — set it and call HandleClick() in the parent's mouse handler.