better color editor

CLAUDE.md

@@ -55,6 +55,9 @@ The core types that were formerly monolithic in `game.rs` are now split into foc
 **`kiln-core/src/cp437.rs`** — tile-index → character mapping (`pub`):
 - `CP437: [char; 256]` — full code-page-437 table (graphic glyphs for 0x00–0x1F, box-drawing for 0xB0–0xDF, etc.). `tile_to_char(tile: u32) -> char` indexes it for `tile < 256`; falls back to `char::from_u32` then a blank space. Unit-tested. Lives in core (not a front-end) because it is the *meaning* of a tile index under the default font; used by kiln-tui's renderer (`render.rs`) and kiln-ui's glyph picker alike.
 
+**`kiln-core/src/colors.rs`** — the named color palette (`pub`):
+- `NAMED_COLORS: [(&str, Rgba8); 16]` — the 16 EGA/VGA palette colors as `(name, color)` pairs in palette order (`Black`, `Blue`, …, `White`). The **single source of truth**: `script::register_global_constants` builds the Rhai `Black`/`Blue`/… `"#RRGGBB"` constants from it, and kiln-ui's glyph picker builds its named-swatch strips from it, so the two never drift.
+
 **`kiln-core/src/archetype.rs`** — element taxonomy:
 - `Archetype` (`Copy`, `PartialEq`, `Hash`) — enum of named element types: `Empty`, `Wall`, `Crate`, `HCrate`, `VCrate`, `Pusher(Direction)`, `ErrorBlock`. Each variant provides `behavior()`, `name()` (used in map files), and `default_glyph()`. `Crate` pushable any direction (CP437 ■, char 254); `HCrate`/`VCrate` pushable east/west (↔, char 29) / north/south (↕, char 18) only. `Pusher(dir)` (`pusher_north|south|east|west`) is a **map-file keyword only**: at load it expands into a scripted object (see [`builtin_scripts`]), never a terrain cell. `ErrorBlock` is a sentinel for unknown archetype names (yellow `?` on red). `TryFrom<&str>` parses by name; unrecognized names return `Err` (the map loader substitutes `ErrorBlock`).
 
@@ -152,12 +155,13 @@ Reusable terminal UI widgets on **ratatui**, mostly **game-agnostic**. A widget
 - `Dialog` draws via its `CursorOverlay` impl (`render(area, buf) -> Option<Position>`; host renders it through `render_overlay`) — dims the screen, draws a centered bordered box. A **text** dialog centers its field box (h+v) with a distinct `FIELD_BG` background so it reads as an input box; a **list** dialog puts the filter field atop the scrolling, selection-highlighted list. Both show an `[enter] OK   [esc] Cancel` footer (OK dimmed when disabled). `render` returns the active field's caret position (the host places the real terminal cursor). Unit-tested (filtering/clamping, OK-enabled rule, Select/Create/Cancel/text outcomes, headless `render`) with a dummy `Ctx`.
 
 **`kiln-ui/src/glyph_dialog.rs`** — the glyph picker (the one kiln-core-dependent widget):
-- `GlyphDialog<Ctx>` — a modal picker for a [`Glyph`] (CP437 tile index + fg/bg colors), same API shape as `Dialog`. Built via `GlyphDialog::new(title, initial: Glyph, on_done)`; `on_done: FnOnce(Option<Glyph>, &mut Ctx)` fires `Some(glyph)` on OK, `None` on cancel. Holds the selected `tile: u32`, two hex-color `TextField`s (`fg`/`bg`, 6 bare hex digits), and a `Focus` (`Grid`/`Fg`/`Bg`).
-- `handle_event(&Event) -> DialogResult` (reuses `dialog::DialogResult`) — `Esc`→`Cancel`; `Enter`→`Submit` only when both color fields parse (`parse_hex6`); `Tab`/`Shift-Tab`/`BackTab` cycle focus; when the grid is focused arrows move the selection in a 32×8 grid (clamped), otherwise keys edit the focused field. `finish(result, &mut Ctx)` fires the callback (a `Submit` with both colors valid yields `Some(Glyph{..})`).
-- Drawing is its `CursorOverlay` impl (`render(area, buf) -> Option<Position>`; host renders it through `render_overlay`) — dims + centered bordered box; renders the 256-char grid via `kiln_core::cp437::tile_to_char` (each glyph drawn in the chosen fg/bg when both colors are valid, else gray-on-black; the selected cell is a bright cursor when the grid is focused, else reversed), the labeled `fg`/`bg` swatch fields (focused label's background highlighted; invalid field boxed red), and the standard footer. Returns the focused color field's caret position (or `None` when the grid is focused). Unit-tested (seed round-trip, focus cycling, grid clamp, invalid-hex disables OK, Submit/Cancel outcomes, headless `render`) with a dummy `Ctx`.
+- `GlyphDialog<Ctx>` — a modal picker for a [`Glyph`] (CP437 tile index + fg/bg colors), same API shape as `Dialog`. Built via `GlyphDialog::new(title, initial: Glyph, on_done)`; `on_done: FnOnce(Option<Glyph>, &mut Ctx)` fires `Some(glyph)` on OK, `None` on cancel. Holds the selected `tile: u32`, two `ColorPicker`s (`fg`/`bg`), and a `Focus` (`Grid`/`FgStrip`/`FgField`/`BgStrip`/`BgField`).
+- `ColorPicker` (private) — one color selector: a `selected` slot index over a strip of the 16 `kiln_core::colors::NAMED_COLORS` swatches plus a final **custom** slot (`CUSTOM == NAMED_COLORS.len()`), and a 6-hex `TextField` that is the **source of truth** (`color()` parses it). Picking a named swatch fills the field via `TextField::set`; the custom slot leaves it user-editable. Seeds from an `Rgba8` by matching a named color (else the custom slot).
+- `handle_event(&Event) -> DialogResult` (reuses `dialog::DialogResult`) — `Esc`→`Cancel`; `Enter`→`Submit` only when both colors resolve; `Tab`/`Shift-Tab`/`BackTab` cycle focus (skipping a color's `*Field` stop unless it's on the custom slot). On the grid, arrows move the 32×8 selection (clamped); on a strip, Left/Right pick a swatch and Down enters the custom field; in a custom field, keys edit it and Up returns to the strip. `finish(result, &mut Ctx)` fires the callback (a `Submit` with both colors valid yields `Some(Glyph{..})`).
+- Drawing is its `CursorOverlay` impl (`render(area, buf) -> Option<Position>`; host renders it through `render_overlay`) — dims + centered bordered box; renders the 256-char grid via `kiln_core::cp437::tile_to_char` (chosen fg/bg when both colors resolve, else gray-on-black; selected cell is a bright cursor when the grid is focused, else reversed), then for each color a **swatch strip** (one solid cell per named color + the custom slot; selected slot marked `●`, custom slot otherwise `+`) above a **hex row** (an editable `#RRGGBB` box, red when invalid, when on the custom slot; else the dimmed name + hex of the selected named color), and the footer (which previews the chosen glyph). Returns the focused custom field's caret position (or `None`). Unit-tested (named/custom seeding, strip selection fills hex, focus cycling skips unreachable fields, Down/Up enters/leaves field, grid clamp, invalid-hex disables OK, Submit/Cancel, headless `render`) with a dummy `Ctx`.
 
 **`kiln-ui/src/text_field.rs`** — a single-line editable text field (a one-line sibling of `code_editor`, used by `dialog`'s text/filter inputs; replaced `tui-input`):
-- `TextField` — `text: String` + a char-indexed `cursor` + a `Clipboard`. `new(initial)`, `value()`, `display_cursor()` (caret's display column), and `handle_key(KeyEvent) -> bool` (`true` if consumed). Handles printable insert, Backspace/Delete, Left/Right (+ ctrl word-moves), Home/End, and `ctrl`/`⌘`+`v` paste (newlines stripped); leaves Esc/Enter/Up/Down to the caller. Presentation is the caller's job (it reads `value()`/`display_cursor()`). No selection yet. Unit-tested (typing, delete, movement, paste, wide-char cursor).
+- `TextField` — `text: String` + a char-indexed `cursor` + a `Clipboard` + an optional `max_length`. `new(initial)` (unbounded) or `sized(initial, max_length)` (truncates the seed and caps typed input); `value()`, `display_cursor()` (caret's display column), `set(text)` (replace contents, truncated to `max_length`), and `handle_key(KeyEvent) -> bool` (`true` if consumed). Handles printable insert, Backspace/Delete, Left/Right (+ ctrl word-moves), Home/End, and `ctrl`/`⌘`+`v` paste (newlines stripped); leaves Esc/Enter/Up/Down to the caller. Presentation is the caller's job (it reads `value()`/`display_cursor()`). No selection yet. Unit-tested (typing, delete, movement, paste, wide-char cursor, max-length cap, `set`).
 
 **`kiln-ui/src/code_editor.rs`** — a hand-written **modeless, keyboard-only** code editor (no editor crate; `edtui` was tried and dropped — it panicked on bare Shift via an `unimplemented!()` keycode arm and lacked basics like line-wrap):
 - `CodeEditor` — edits one script's text: `lines: Vec<String>`, a char-indexed `cursor`/`anchor` (selection), `desired_col` (vertical-move column), `scroll` (top row + left display-col, cursor-following), undo/redo `Snapshot` stacks, a cached `HighlightParts`, and a `Clipboard` (system via `arboard` when available, always backed by an internal buffer so copy/paste work headless / on the web). Public API (unchanged across the edtui→custom swap, so kiln-tui needed no edits): `new(name, text)`, `name()`, `text()` (lines joined with `\n`), `handle_event(&Event) -> CodeEditorOutcome { Continue, Exit }`, `draw(&mut self, frame, area)`.