Fix gain deep dashboard layout

[malochapo]

Summary

• remove repeated cmds suffix from each RECENT DAYS row
• add a boxed spacer between the gain score bar and trend: row
• add a focused regression test for both layout invariants

Validation

• cargo test --lib deep_dashboard_separates_score_bar_and_omits_recent_day_cmd_suffix -- --nocapture
• cargo fmt --check
• git diff --check
• cargo run --quiet -- gain --deep

Issue

Could not create an upstream issue from this token because the authenticated account has READ permission on yvgude/lean-ctx; the fork has issues disabled.

Fixes #1242

[github-actions]

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[malochapo]

I have read the CLA Document and I hereby sign the CLA

[malochapo]

(nb already signed CLA few weeks ago, maybe something's wrong ?)