fix: tap-hold-opposite-hand-release skips same-hand keys when held

[viktomas]

👋 hello, when I used the tap-hold-opposite-hand-release and pressed f+d for ctrl and shift modifiers and then pressed j, it outputted ctrl+d and ignored the f. Below is an AI-generated fix with tests. Feel free to close the issue since I didn't put too much effort into reviewing. But the fix works on my machine

Problem

tap-hold-opposite-hand-release with (same-hand tap) incorrectly resolves as Hold when two same-hand HRM keys are pressed together followed by an opposite-hand key.

Reproduction: Given left-hand HRM keys f→ctrl and d→shift, and right-hand key j:

d:f t:5 d:d t:20 d:j t:20 u:j

Expected: f resolves as Tap (same-hand d was pressed)
Actual: f resolves as Hold(ctrl), outputting ctrl+d

Root cause

The -release variant checks for both press+release in the queue before checking which hand a key belongs to:

// Wait for the interrupting key's release before deciding.
let release = Event::Release(i, j);
if !queued.clone().copied().any(|q| q.event() == release) {
    continue; // ← same-hand keys skipped when still held!
}
// hand check happens here, too late

When f is waiting and the queue contains [d↓, j↓, j↑]:

1. d↓ — looks for d↑ — not found (d still held) → continue (skipped)
2. j↓ — looks for j↑ — found → opposite hand → Hold

The same-hand key d is invisible because it hasn't been released yet.

Fix

Move the release check after the hand check. Only opposite-hand, neutral, and unknown-hand keys require press+release. Same-hand keys resolve immediately on press — matching tap-hold-opposite-hand (non-release variant) behavior for same-hand decisions.

This is correct because the -release requirement exists to prevent misfires on fast cross-hand overlaps (e.g., f↓ j↓ f↑ j↑ should be fj, not ctrl+j). Same-hand keys don't need this protection — they already resolve as Tap structurally.

Checklist

• Add documentation to docs/config.adoc
  • N/A - it's a bug fix
• Add example and basic docs to cfg_samples/kanata.kbd
• N/A - it's a bug fix
• Update error messages
• N/A - it's a bug fix
• Added tests, or did manual testing
  • Yes both automated and manual testing

[viktomas]

This actually works quite well for me, if you would be tempted to close the issue, please let me know what's missing and I can try to add it 🙇