fix(cli): make refresh_interval configurable, default to 0 (disabled)

[OYLFLMH]

Problem

Commit 6724daa2c ("fix: keep CLI idle timer ticking #45592") added refresh_interval=1.0 to the prompt_toolkit Application in non-fullscreen classic CLI mode. This causes a full UI redraw every second during idle time.

Terminal emulators with "auto-scroll on output" (Xshell, iTerm2, Windows Terminal, etc.) interpret the ANSI output from each redraw as new content and auto-scroll the viewport to the bottom — even when the user has manually scrolled up to read conversation history.

Fixes: #48309

Root Cause

The original code explicitly warned against this (cli.py ~L12927 before 6724daa2c):

# Do not repaint the idle prompt every second. In non-full-screen
# prompt_toolkit mode, background redraws can fight tmux/Ghostty/cmux
# viewport restoration after focus changes...

Change

Drive refresh_interval from display.cli_refresh_interval in config.yaml, defaulting to 0 (disabled — the pre-0.15.2 behavior). Users who want the idle clock to keep ticking can set it to 1.0 (or any positive value).

cli.py (1 line change)

# Before (hardcoded):
refresh_interval=1.0,

# After (config-driven, default 0 = off):
refresh_interval=float(CLI_CONFIG.get("display", {}).get("cli_refresh_interval", 0)),

hermes_cli/config.py (1 key added)

"cli_refresh_interval": 0,  # seconds; 0 = disabled

Testing

• python3 -m py_compile cli.py hermes_cli/config.py — passes
• scripts/run_tests.sh tests/cli/ — 78 files, 924 tests, 0 failures
• Manual verification: idle scrolling stays put on Xshell (SSH)

[OYLFLMH]

Closing — the feature was implemented upstream in v0.17.0 (commit 2bd1977) with the same config key (display.cli_refresh_interval) and identical cli.py implementation.

The only difference is the default value: this PR used 0 (disabled), upstream chose 1.0 (enabled, preserving the #45592 clock-ticking fix) with the option to set 0 for terminals affected by #48309.

Both approaches are valid — upstream's choice keeps the existing behavior as default while allowing opt-out, which is the more conservative migration path. No further action needed on this PR.