feat(tui): personal TUI rework, integrating upstream model reasoning-effort selection

Consolidates the personal dsh-tui customizations (module split into
components/session/extension, prompt template + running-glyph indicator,
copyable transcript, tool-card headers, timing placement, XML tool output,
status/footer rework) and ports upstream's model reasoning-effort selector
(Shift+Tab effort cycling, effort-aware /model, footer, and /status) onto
the personal module layout.

packages/ui/tui/src/components/theme.ts

@@ -0,0 +1,184 @@
+/**
+ * Theme-agnostic ANSI palette and derived pi-tui themes for the terminal front
+ * door. The palette is built from the standard 16-color ANSI set plus SGR
+ * attributes so every terminal remaps it to its active color scheme.
+ * @module @deepseek-ai/dsh-tui/components/theme
+ */
+
+import type {
+  MarkdownTheme,
+  SelectListTheme,
+  TerminalColorScheme,
+} from '@earendil-works/pi-tui'
+
+/** Theme-agnostic role colors and SGR attribute wrappers. */
+export interface Palette {
+  accent: (text: string) => string
+  accent2: (text: string) => string
+  text: (text: string) => string
+  muted: (text: string) => string
+  dim: (text: string) => string
+  success: (text: string) => string
+  warning: (text: string) => string
+  error: (text: string) => string
+  code: (text: string) => string
+  added: (text: string) => string
+  removed: (text: string) => string
+  bold: (text: string) => string
+  italic: (text: string) => string
+  underline: (text: string) => string
+  strike: (text: string) => string
+  /** Reverse video for the active selection; swaps the theme's own fg/bg so it reads on any scheme. */
+  selected: (text: string) => string
+}
+
+function ansi(open: string, close: string, enabled: boolean): (text: string) => string {
+  return enabled ? text => `\x1b[${open}m${text}\x1b[${close}m` : text => text
+}
+
+/**
+ * Theme-agnostic palette built from the standard 16-color ANSI set plus SGR
+ * attributes, which every terminal remaps to its active color scheme. Body
+ * `text` stays the terminal's default foreground so it reads on light and dark
+ * backgrounds alike; grouping uses foreground-only bold, underlined role
+ * headers and reverse video rather than fixed background fills or per-line
+ * prefixes, so a transcript drag-select copies message text without stray
+ * glyphs.
+ *
+ * @param enabled - Whether ANSI is emitted at all.
+ * @param scheme - Active terminal color scheme; adjusts dim and code roles.
+ * @returns The role palette for the given scheme.
+ */
+export function createPalette(enabled: boolean, scheme: TerminalColorScheme = 'dark'): Palette {
+  return {
+    accent: ansi('94', '39', enabled),
+    accent2: ansi('95', '39', enabled),
+    text: text => text,
+    muted: ansi('90', '39', enabled),
+    // SGR 2 (dim) lightens text on a light background — substitute ANSI 90
+    // (bright black / gray) which renders as a readable muted tone on any scheme.
+    dim: scheme === 'light' ? ansi('90', '39', enabled) : ansi('2', '22', enabled),
+    success: ansi('32', '39', enabled),
+    warning: ansi('33', '39', enabled),
+    error: ansi('31', '39', enabled),
+    // ANSI 36 (cyan) is difficult to read on a light background — use
+    // ANSI 34 (blue) which is legible on both light and dark schemes.
+    code: scheme === 'light' ? ansi('34', '39', enabled) : ansi('36', '39', enabled),
+    added: ansi('32', '39', enabled),
+    removed: ansi('31', '39', enabled),
+    bold: ansi('1', '22', enabled),
+    italic: ansi('3', '23', enabled),
+    underline: ansi('4', '24', enabled),
+    strike: ansi('9', '29', enabled),
+    selected: ansi('7', '27', enabled),
+  }
+}
+
+/**
+ * DeepSeek brand gradient stops (indigo → light blue) taken from the
+ * deepseek.com logo, painted across the startup banner's product name on
+ * truecolor terminals. Fixed brand identity, deliberately outside the
+ * theme-adaptive {@link Palette}.
+ */
+const BRAND_GRADIENT = [
+  [77, 107, 254], // #4D6BFE
+  [57, 130, 255], // #3982FF
+  [36, 152, 255], // #2498FF
+] as const
+
+/**
+ * Sample {@link BRAND_GRADIENT} at fraction `t` via piecewise-linear
+ * interpolation across its stops.
+ *
+ * @param t - Position along the gradient; clamped to [0, 1].
+ * @returns The interpolated `[r, g, b]` channels, each rounded to 0–255.
+ */
+function brandColorAt(t: number): readonly [number, number, number] {
+  const span = Math.min(Math.max(t, 0), 1) * (BRAND_GRADIENT.length - 1)
+  const index = Math.min(Math.floor(span), BRAND_GRADIENT.length - 2)
+  const local = span - index
+  // `index` is clamped to a valid adjacent pair, so both lookups are in-bounds.
+  const from = BRAND_GRADIENT[index] as readonly [number, number, number]
+  const to = BRAND_GRADIENT[index + 1] as readonly [number, number, number]
+  return [
+    Math.round(from[0] + (to[0] - from[0]) * local),
+    Math.round(from[1] + (to[1] - from[1]) * local),
+    Math.round(from[2] + (to[2] - from[2]) * local),
+  ]
+}
+
+/**
+ * Paint `text` left-to-right in the DeepSeek brand gradient with per-character
+ * 24-bit foreground codes, resetting to the default foreground at the end.
+ * Foreground-only, so it stays legible on any terminal background; the caller
+ * gates it on truecolor support and wraps it in bold.
+ *
+ * @param text - Text to colorize; sampled once per character.
+ * @returns `text` wrapped in truecolor SGR foreground codes.
+ */
+export function gradientText(text: string): string {
+  // The sole caller passes the ASCII product name, so UTF-16 unit iteration
+  // samples exactly one color per visible letter.
+  const last = Math.max(1, text.length - 1)
+  let painted = ''
+  for (let index = 0; index < text.length; index += 1) {
+    const [r, g, b] = brandColorAt(index / last)
+    painted += `\x1b[38;2;${r};${g};${b}m${text.charAt(index)}`
+  }
+  return `${painted}\x1b[39m`
+}
+
+/**
+ * Derive the pi-tui Markdown theme from a role palette.
+ * @param palette - Active role palette.
+ * @returns The Markdown theme wired to palette roles.
+ */
+export function markdownTheme(palette: Palette): MarkdownTheme {
+  return {
+    heading: text => palette.accent(text),
+    link: text => palette.accent(text),
+    // pi-tui requires this URL slot but its current Markdown renderer does not invoke it.
+    /* v8 ignore next */
+    linkUrl: text => palette.dim(text),
+    code: text => palette.code(text),
+    codeBlock: text => palette.code(text),
+    // pi-tui presents both fence rows through this callback. Keep the opening
+    // language label, but hide Markdown syntax and the otherwise-empty close.
+    codeBlockBorder: text => palette.dim(text.slice(3)),
+    quote: text => palette.muted(text),
+    quoteBorder: text => palette.accent2(text),
+    hr: text => palette.dim(text),
+    listBullet: text => palette.accent(text),
+    bold: text => palette.bold(text),
+    italic: text => palette.italic(text),
+    strikethrough: text => palette.strike(text),
+    underline: text => palette.underline(text),
+  }
+}
+
+/**
+ * Derive the pi-tui select-list theme from a role palette.
+ * @param palette - Active role palette.
+ * @returns The select-list theme wired to palette roles.
+ */
+export function selectTheme(palette: Palette): SelectListTheme {
+  return {
+    selectedPrefix: palette.accent,
+    selectedText: palette.accent,
+    description: palette.muted,
+    scrollInfo: palette.dim,
+    noMatch: palette.warning,
+  }
+}
+
+/**
+ * Derive the reverse-video dialog select-list theme from a role palette.
+ * @param palette - Active role palette.
+ * @returns The dialog select-list theme with a reverse-video selection.
+ */
+export function dialogSelectTheme(palette: Palette): SelectListTheme {
+  return {
+    ...selectTheme(palette),
+    selectedText: text => palette.selected(palette.accent(text)),
+  }
+}