fix(tui): restore macOS copy behavior and theme polish (#17131)

This PR groups the TUI fixes that restore macOS Terminal usability and clean up the theme/composer regressions:

- copy transcript selections on macOS drag-release so Terminal.app users can copy while mouse tracking is enabled
- copy composer selections on macOS drag-release; composer selection is internal to TextInput and does not use the global Ink selection bus
- keep IDE Cmd+C forwarding setup macOS-only, and make keybinding conflict checks respect simple when-clause overlap/negation
- force truecolor before chalk initializes (unless NO_COLOR / FORCE_COLOR / HERMES_TUI_TRUECOLOR opt-outs apply) so the default banner keeps its gold/amber/bronze gradient in Terminal.app
- move TUI surfaces onto semantic theme tokens and preserve skin prompt symbols as bare tokens with renderer-owned spacing
- render focused placeholders as dim hint text in TTY mode instead of inverse/selected-looking synthetic cursor text

ui-tui/src/__tests__/forceTruecolor.test.ts

@@ -0,0 +1,64 @@
+import { describe, expect, it } from 'vitest'
+
+const ENV_KEYS = ['COLORTERM', 'FORCE_COLOR', 'HERMES_TUI_TRUECOLOR', 'NO_COLOR'] as const
+
+async function withCleanEnv(setup: () => void, body: () => Promise<void>) {
+  const saved: Record<string, string | undefined> = {}
+
+  for (const k of ENV_KEYS) {
+    saved[k] = process.env[k]
+    delete process.env[k]
+  }
+
+  try {
+    setup()
+    await body()
+  } finally {
+    for (const k of ENV_KEYS) {
+      if (saved[k] === undefined) {
+        delete process.env[k]
+      } else {
+        process.env[k] = saved[k]
+      }
+    }
+  }
+}
+
+describe('forceTruecolor', () => {
+  it('sets COLORTERM=truecolor and FORCE_COLOR=3 when unset', async () => {
+    await withCleanEnv(
+      () => {},
+      async () => {
+        await import('../lib/forceTruecolor.js?t=' + Date.now())
+        expect(process.env.COLORTERM).toBe('truecolor')
+        expect(process.env.FORCE_COLOR).toBe('3')
+      }
+    )
+  })
+
+  it('respects HERMES_TUI_TRUECOLOR=0 opt-out', async () => {
+    await withCleanEnv(
+      () => {
+        process.env.HERMES_TUI_TRUECOLOR = '0'
+      },
+      async () => {
+        await import('../lib/forceTruecolor.js?t=optout-' + Date.now())
+        expect(process.env.COLORTERM).toBeUndefined()
+        expect(process.env.FORCE_COLOR).toBeUndefined()
+      }
+    )
+  })
+
+  it('respects NO_COLOR', async () => {
+    await withCleanEnv(
+      () => {
+        process.env.NO_COLOR = '1'
+      },
+      async () => {
+        await import('../lib/forceTruecolor.js?t=no-color-' + Date.now())
+        expect(process.env.COLORTERM).toBeUndefined()
+        expect(process.env.FORCE_COLOR).toBeUndefined()
+      }
+    )
+  })
+})

ui-tui/src/__tests__/platform.test.ts

@@ -51,6 +51,12 @@ describe('isCopyShortcut', () => {
 
     expect(isCopyShortcut({ ctrl: false, meta: true, super: false }, 'c', {})).toBe(false)
   })
+
+  it('accepts the VS Code/Cursor forwarded Cmd+C copy sequence on macOS', async () => {
+    const { isCopyShortcut } = await importPlatform('darwin')
+
+    expect(isCopyShortcut({ ctrl: true, meta: false, super: true }, 'c', {})).toBe(true)
+  })
 })
 
 describe('isVoiceToggleKey', () => {

ui-tui/src/__tests__/streamingMarkdown.test.ts

@@ -74,6 +74,6 @@ describe('streaming theme assumption', () => {
     // Sanity that the theme we pass doesn't change shape. Component import
     // already happens above — this is a smoke test that the module graph
     // for streamingMarkdown wires up without cycles.
-    expect(DEFAULT_THEME.color.amber).toBeTruthy()
+    expect(DEFAULT_THEME.color.accent).toBeTruthy()
   })
 })

ui-tui/src/__tests__/syntax.test.ts

@@ -19,16 +19,16 @@ describe('syntax highlighter', () => {
   it('paints a whole-line comment dim', () => {
     const tokens = highlightLine('// hello', 'ts', t)
 
-    expect(tokens).toEqual([[t.color.dim, '// hello']])
+    expect(tokens).toEqual([[t.color.muted, '// hello']])
   })
 
   it('paints keywords, strings, and numbers in a ts line', () => {
     const tokens = highlightLine(`const x = 'hi' + 42`, 'ts', t)
     const colors = tokens.map(tok => tok[0])
 
-    expect(colors).toContain(t.color.bronze) // const
-    expect(colors).toContain(t.color.amber) // 'hi'
-    expect(colors).toContain(t.color.cornsilk) // 42
+    expect(colors).toContain(t.color.border) // const
+    expect(colors).toContain(t.color.accent) // 'hi'
+    expect(colors).toContain(t.color.text) // 42
   })
 
   it('falls through unchanged for unknown langs', () => {
@@ -40,6 +40,6 @@ describe('syntax highlighter', () => {
   it('treats `#` as a python comment, not a selector', () => {
     const tokens = highlightLine('# comment', 'py', t)
 
-    expect(tokens).toEqual([[t.color.dim, '# comment']])
+    expect(tokens).toEqual([[t.color.muted, '# comment']])
   })
 })

ui-tui/src/__tests__/terminalParity.test.ts

@@ -28,6 +28,12 @@ describe('terminalParityHints', () => {
   it('suppresses IDE setup hint when keybindings are already configured', async () => {
     const readFile = vi.fn().mockResolvedValue(
       JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'workbench.action.terminal.sendSequence',
+          when: 'terminalFocus && terminalTextSelected',
+          args: { text: '\u001b[99;13u' }
+        },
         {
           key: 'shift+enter',
           command: 'workbench.action.terminal.sendSequence',

ui-tui/src/__tests__/terminalSetup.test.ts

@@ -79,11 +79,34 @@ describe('configureTerminalKeybindings', () => {
     expect(writeFile).toHaveBeenCalledTimes(1)
     expect(copyFile).not.toHaveBeenCalled() // no existing file to back up
     const written = writeFile.mock.calls[0]?.[1] as string
+    expect(written).toContain('cmd+c')
+    expect(written).toContain('terminalTextSelected')
+    expect(written).toContain('\\u001b[99;13u')
     expect(written).toContain('shift+enter')
     expect(written).toContain('cmd+enter')
     expect(written).toContain('cmd+z')
   })
 
+  it('only adds the Cmd+C forwarding binding on macOS', async () => {
+    const mkdir = vi.fn().mockResolvedValue(undefined)
+    const readFile = vi.fn().mockRejectedValue(Object.assign(new Error('missing'), { code: 'ENOENT' }))
+    const writeFile = vi.fn().mockResolvedValue(undefined)
+    const copyFile = vi.fn().mockResolvedValue(undefined)
+
+    const result = await configureTerminalKeybindings('vscode', {
+      fileOps: { copyFile, mkdir, readFile, writeFile },
+      homeDir: '/home/me',
+      platform: 'linux'
+    })
+
+    expect(result.success).toBe(true)
+    const written = writeFile.mock.calls[0]?.[1] as string
+    expect(written).not.toContain('cmd+c')
+    expect(written).not.toContain('terminalTextSelected')
+    expect(written).not.toContain('\\u001b[99;13u')
+    expect(written).toContain('shift+enter')
+  })
+
   it('reports conflicts without overwriting existing bindings', async () => {
     const mkdir = vi.fn().mockResolvedValue(undefined)
 
@@ -113,6 +136,118 @@ describe('configureTerminalKeybindings', () => {
     expect(copyFile).not.toHaveBeenCalled() // no backup when not writing
   })
 
+  it('flags a global (when-less) binding on the same key as a conflict', async () => {
+    // A user's keybindings.json `cmd+c` with no `when` clause is global —
+    // it overlaps any context, including our terminal scope. We must NOT
+    // silently add a terminal-scoped cmd+c that would shadow it.
+    const mkdir = vi.fn().mockResolvedValue(undefined)
+    const readFile = vi.fn().mockResolvedValue(
+      JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'myExtension.smartCopy'
+        }
+      ])
+    )
+    const writeFile = vi.fn().mockResolvedValue(undefined)
+    const copyFile = vi.fn().mockResolvedValue(undefined)
+
+    const result = await configureTerminalKeybindings('vscode', {
+      fileOps: { copyFile, mkdir, readFile, writeFile },
+      homeDir: '/Users/me',
+      platform: 'darwin'
+    })
+
+    expect(result.success).toBe(false)
+    expect(result.message).toContain('cmd+c')
+    expect(writeFile).not.toHaveBeenCalled()
+  })
+
+  it('flags an overlapping terminal-context binding as a conflict', async () => {
+    // Existing `cmd+c` scoped to plain `terminalFocus` overlaps with our
+    // `terminalFocus && terminalTextSelected` — both fire when the
+    // terminal is focused with text selected, so the existing binding
+    // would shadow ours. Treat as a conflict even though the strings
+    // aren't identical.
+    const mkdir = vi.fn().mockResolvedValue(undefined)
+    const readFile = vi.fn().mockResolvedValue(
+      JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'workbench.action.terminal.copySelection',
+          when: 'terminalFocus'
+        }
+      ])
+    )
+    const writeFile = vi.fn().mockResolvedValue(undefined)
+    const copyFile = vi.fn().mockResolvedValue(undefined)
+
+    const result = await configureTerminalKeybindings('vscode', {
+      fileOps: { copyFile, mkdir, readFile, writeFile },
+      homeDir: '/Users/me',
+      platform: 'darwin'
+    })
+
+    expect(result.success).toBe(false)
+    expect(result.message).toContain('cmd+c')
+    expect(writeFile).not.toHaveBeenCalled()
+  })
+
+  it('does not flag a negated terminalTextSelected binding as a conflict', async () => {
+    // A binding scoped to "terminal focused but no selected text" is
+    // logically disjoint from our copy-forwarding binding, which requires
+    // terminalTextSelected.
+    const mkdir = vi.fn().mockResolvedValue(undefined)
+    const readFile = vi.fn().mockResolvedValue(
+      JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'workbench.action.terminal.sendSequence',
+          when: 'terminalFocus && !terminalTextSelected',
+          args: { text: '\u0003' }
+        }
+      ])
+    )
+    const writeFile = vi.fn().mockResolvedValue(undefined)
+    const copyFile = vi.fn().mockResolvedValue(undefined)
+
+    const result = await configureTerminalKeybindings('vscode', {
+      fileOps: { copyFile, mkdir, readFile, writeFile },
+      homeDir: '/Users/me',
+      platform: 'darwin'
+    })
+
+    expect(result.success).toBe(true)
+    expect(writeFile).toHaveBeenCalledTimes(1)
+  })
+
+  it('does not flag a disjoint-when binding on the same key as a conflict', async () => {
+    // VS Code allows multiple bindings for the same key when their `when`
+    // clauses don't overlap. A user's pre-existing cmd+c binding scoped to
+    // editor focus should NOT block our terminal-scoped cmd+c binding.
+    const mkdir = vi.fn().mockResolvedValue(undefined)
+    const readFile = vi.fn().mockResolvedValue(
+      JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'editor.action.clipboardCopyAction',
+          when: 'editorFocus'
+        }
+      ])
+    )
+    const writeFile = vi.fn().mockResolvedValue(undefined)
+    const copyFile = vi.fn().mockResolvedValue(undefined)
+
+    const result = await configureTerminalKeybindings('vscode', {
+      fileOps: { copyFile, mkdir, readFile, writeFile },
+      homeDir: '/Users/me',
+      platform: 'darwin'
+    })
+
+    expect(result.success).toBe(true)
+    expect(writeFile).toHaveBeenCalledTimes(1)
+  })
+
   it('backs up existing keybindings.json only when writing changes', async () => {
     const mkdir = vi.fn().mockResolvedValue(undefined)
     const readFile = vi.fn().mockResolvedValue(JSON.stringify([]))
@@ -186,6 +321,12 @@ describe('configureTerminalKeybindings', () => {
 
     const readComplete = vi.fn().mockResolvedValue(
       JSON.stringify([
+        {
+          key: 'cmd+c',
+          command: 'workbench.action.terminal.sendSequence',
+          when: 'terminalFocus && terminalTextSelected',
+          args: { text: '\u001b[99;13u' }
+        },
         {
           key: 'shift+enter',
           command: 'workbench.action.terminal.sendSequence',

ui-tui/src/__tests__/textInputWrap.test.ts

@@ -44,6 +44,7 @@ describe('input metrics helpers', () => {
 
   it('reserves gutters on wide panes without starving narrow composer width', () => {
     expect(stableComposerColumns(100, 3)).toBe(93)
+    expect(stableComposerColumns(100, 5)).toBe(91)
     expect(stableComposerColumns(10, 3)).toBe(5)
     expect(stableComposerColumns(6, 3)).toBe(1)
   })

ui-tui/src/__tests__/theme.test.ts

@@ -44,7 +44,7 @@ describe('DEFAULT_THEME', () => {
   it('has color palette', async () => {
     const { DEFAULT_THEME } = await importThemeWithCleanEnv()
 
-    expect(DEFAULT_THEME.color.gold).toBe('#FFD700')
+    expect(DEFAULT_THEME.color.primary).toBe('#FFD700')
     expect(DEFAULT_THEME.color.error).toBe('#ef5350')
   })
 })
@@ -53,9 +53,9 @@ describe('LIGHT_THEME', () => {
   it('avoids bright-yellow accents unreadable on white backgrounds (#11300)', async () => {
     const { LIGHT_THEME } = await importThemeWithCleanEnv()
 
-    expect(LIGHT_THEME.color.gold).not.toBe('#FFD700')
-    expect(LIGHT_THEME.color.amber).not.toBe('#FFBF00')
-    expect(LIGHT_THEME.color.dim).not.toBe('#B8860B')
+    expect(LIGHT_THEME.color.primary).not.toBe('#FFD700')
+    expect(LIGHT_THEME.color.accent).not.toBe('#FFBF00')
+    expect(LIGHT_THEME.color.muted).not.toBe('#B8860B')
     expect(LIGHT_THEME.color.statusWarn).not.toBe('#FFD700')
   })
 
@@ -180,13 +180,22 @@ describe('fromSkin', () => {
   it('overrides banner colors', async () => {
     const { fromSkin } = await importThemeWithCleanEnv()
 
-    expect(fromSkin({ banner_title: '#FF0000' }, {}).color.gold).toBe('#FF0000')
+    expect(fromSkin({ banner_title: '#FF0000' }, {}).color.primary).toBe('#FF0000')
   })
 
   it('preserves unset colors', async () => {
     const { DEFAULT_THEME, fromSkin } = await importThemeWithCleanEnv()
 
-    expect(fromSkin({ banner_title: '#FF0000' }, {}).color.amber).toBe(DEFAULT_THEME.color.amber)
+    expect(fromSkin({ banner_title: '#FF0000' }, {}).color.accent).toBe(DEFAULT_THEME.color.accent)
+  })
+
+  it('derives completion current background from resolved completion background', async () => {
+    const { fromSkin } = await importThemeWithCleanEnv()
+
+    const theme = fromSkin({ banner_accent: '#000000', completion_menu_bg: '#ffffff' }, {})
+
+    expect(theme.color.completionBg).toBe('#ffffff')
+    expect(theme.color.completionCurrentBg).toBe('#bfbfbf')
   })
 
   it('overrides branding', async () => {
@@ -197,6 +206,14 @@ describe('fromSkin', () => {
     expect(brand.prompt).toBe('$')
   })
 
+  it('normalizes skin prompt symbols to trimmed single-line text', async () => {
+    const { DEFAULT_THEME, fromSkin } = await importThemeWithCleanEnv()
+
+    expect(fromSkin({}, { prompt_symbol: ' ⚔ ❯ \n' }).brand.prompt).toBe('⚔ ❯')
+    expect(fromSkin({}, { prompt_symbol: ' Ψ > \n' }).brand.prompt).toBe('Ψ >')
+    expect(fromSkin({}, { prompt_symbol: '\n\t' }).brand.prompt).toBe(DEFAULT_THEME.brand.prompt)
+  })
+
   it('defaults for empty skin', async () => {
     const { DEFAULT_THEME, fromSkin } = await importThemeWithCleanEnv()