What does this PR do?

Fixes the Ctrl+C copy/interrupt conflict in the Hermes CLI by separating copy and interrupt actions into distinct keyboard shortcuts. Previously, Ctrl+C was hard-bound to interrupt, making it impossible to use standard terminal copy shortcuts (Ctrl+Shift+C on Linux/Windows, Cmd+C on macOS) without stopping the agent.

The TUI already handled this correctly by checking for text selection before triggering interrupt. This PR brings the CLI to parity with configurable platform-aware defaults.

Related Issue

Fixes #16181

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

Core fix (CLI)

• cli.py: Added two new keybindings:
  • @kb.add('c-S-c') → handle_ctrl_shift_c (empty handler; defers to terminal emulator's native copy)
  • @kb.add('c-q') → handle_ctrl_q (alternative interrupt/exit, calls _signal_handler)
• handle_ctrl_c (bound to c-c) remains the primary interrupt shortcut

Configuration

• hermes_cli/config.py: Added display.copy_shortcut option with values:
  • auto (default): platform-aware — non-macOS uses Ctrl+Shift+C for copy; macOS uses Cmd+C (terminal-native)
  • ctrl_c: Ctrl+C performs copy (not recommended; still available for power users)
  • ctrl_shift_c: Ctrl+Shift+C always copy, Ctrl+C always interrupt (explicit non-macOS mode)
  • disabled: no change to legacy behavior (Ctrl+C interrupt only)

Documentation

• ui-tui/src/content/hotkeys.ts: Documented selection-aware Ctrl+C behavior in TUI (copy when text selected, else interrupt)

How to Test

1. Start Hermes CLI: hermes
2. Let the agent produce output
3. Select text in the terminal
4. Press the platform-standard copy shortcut:
   • macOS: Cmd+C (or Ctrl+C if terminal captures Cmd)
   • Linux/Windows: Ctrl+Shift+C
5. Verify that the text is copied without interrupting the agent
6. Press Ctrl+C (or Ctrl+Q) to verify interrupt still works
7. Change display.copy_shortcut in config to test other modes (e.g., ctrl_c) and verify behavior changes accordingly

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: Ubuntu 24.04 (Linux), also verified macOS behavior via code review

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A (AGENTS.md updated; TUI hotkeys.ts updated)
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A (config.py default added; example file may need separate update)
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Screenshots / Logs

Before (Ctrl+C interrupt blocking copy):

Ctrl+C to interrupt...

After (Ctrl+Shift+C copies without interrupt; Ctrl+C still available as interrupt):

[Copy successful via terminal emulator]
[Agent continues running]