Flagship Demo — Midnight Commander-like TUI file browser (libc-free)

• Type: feature
• Status: done
• Owner: — (lock released; last worked by Codex)
• Opened: 2026-06-21
• Relation: Sibling to other flagship demos. Depends on the low-level directory scanning in feature-sys-getdents and unbuffered terminal input in feature-rtl-terminal-raw-mode.

Goal

An interactive terminal file manager (examples/fm/) supporting multiple pane layouts (1, 2, 3, or 4 active panes) and GUI-style tile view modes with live true-color previews (text and PNG thumbnails) using ansirender's quadrant-plus-detail engine.

Specification

• Panes: Divide terminal columns equally among active panes. Switch focus via Tab / Shift-Tab.
• View Modes:
  • compact: name, size, optional modification date.
  • tile: tiles containing names and a live preview card.
• Preview Card Engine:
  • Text files: Display the first 10 lines.
  • PNG files: Render a thumbnail using the true-color quadrant-plus-detail engine.
  • Unsupported files: Display a colored placeholder icon indicating file format type.
• Controls: Interactive shortcut keys (e.g. F1..F4 to adjust pane counts, Enter to navigate folders, Arrow keys to scroll).

Log

• 2026-06-21 — Opened.

• 2026-06-21 — First source slice in progress: examples/fm/fm.pas lists one or two terminal panes using SysUtils.GetDirectoryContents and ANSI rendering. Current slice is non-interactive and shows names/type only; stat metadata, previews, and raw-key navigation remain in this ticket or its library blockers.

• 2026-06-21 — HALTED → unfinished/. working/ lock released (no active agent). First demo slice committed as 9d4a162 (examples/fm/fm.pas); needs stat metadata, previews, raw-key nav.

• 2026-06-22 — DONE in this commit. Expanded examples/fm/fm.pas into a one-shot/interactive terminal browser with 1-4 panes, compact/tile modes, stat-backed size display, raw-key controls (--interactive), text previews, PNG thumbnails through PngDecodeRGBA + RenderAnsiTrueColorQuadrant, and colored placeholders for other file types. The default render remains one-shot for deterministic smoke. Verified direct compile/run in compact and tile mode plus make demos.