fix(cli): honor an explicit /journey --reveal 0 instead of rendering 100%

[hashbender]

What does this PR do?

Makes an explicit /journey --reveal 0 render the oldest (0%) frame instead of the fully-revealed (100%) one.

_cmd_show (hermes_cli/journey.py) coerces the flag with:

reveal = _clamp(float(getattr(args, "reveal", 1.0) or 1.0), 0.0, 1.0)

--reveal 0 parses (argparse type=float) to 0.0, which is falsy, so or 1.0 silently replaces it with the default — the exact opposite of what the flag's own help text documents ("0=oldest, 1=now"). Reachable from both hermes journey --reveal 0 and the interactive /journey --reveal 0. Every other value (0.25, 0.5, …) works, which makes the endpoint failure look like a rendering bug rather than an argument-parsing one.

The fix treats only a missing value as the fully-revealed default; 0.0 clamps through unchanged.

Related Issue

None filed; introduced with the /journey feature (NousResearch#55555).

Type of Change

• Bug fix (non-breaking change which fixes an issue)

Changes Made

• hermes_cli/journey.py — replace the falsy-swallowing or 1.0 with an explicit None-check (+ comment).
• tests/hermes_cli/test_journey_render.py — 3 contract tests running the real args.func path and asserting the reveal value that reaches the frame renderer: --reveal 0 → 0.0, no flag → 1.0, --reveal 0.25 → passthrough.

How to Test

scripts/run_tests.sh tests/hermes_cli/test_journey_render.py

test_reveal_zero_renders_oldest_frame fails on current main (renderer receives 1.0) and passes with the fix; the other 4 tests (including the two pre-existing ANSI-routing contracts) pass on both. macOS 15. scripts/check-windows-footguns.py clean.

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (N/A — behavior now matches the existing help text)
• My changes generate no new warnings
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally with my changes

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Mirror-of: NousResearch#57095
NousResearch#57095