Thanks for the PR, but I think this overlaps with code that already exists, and the guard logic looks inverted. Worth a look before this gets merged.

1. Manual double-tap detection already exists

static/sessions.js lines ~1733-1797 already implements double-click → rename via a pointerup-based handler with _lastTapTime tracking. Quoting the comment in the existing code:

// Use pointerup + manual double-tap detection instead of onclick/ondblclick.
// onclick/ondblclick are unreliable on touch devices (iPad Safari especially):
// hover-triggered layout shifts, ghost clicks, and 300ms delay all break
// single-tap navigation. pointerup fires immediately on both mouse & touch.

That handler calls startRename() on the second pointerup within 350ms. Adding el.ondblclick on top of it means on a desktop double-click both handlers fire — the second pointerup calls startRename() first, sets _renamingSid, then dblclick arrives and short-circuits on the if(_renamingSid) return; guard. Functionally that "works" but it's two parallel mechanisms doing the same job.

What specific failure mode were you seeing where the existing pointerup-based double-tap was not opening the rename UI? On which platform/browser? If the existing handler is broken on some path, fixing that handler is probably better than layering a second handler on top.

2. The _loadingSessionId guard reads inverted

if (_loadingSessionId && _loadingSessionId !== s.session_id) return;

This blocks rename when _loadingSessionId is set and the session being renamed is not the one loading. So if session B is currently loading, you can't rename session A while you wait — but you can rename session B (the one that's actually mid-load).

I think the intent was the opposite: prevent renaming a session whose load is still in progress, while letting the user rename other sidebar items freely. That would be:

if (_loadingSessionId === s.session_id) return;

Is the inverted form intentional? The PR description says "prevent renaming loading sessions" which matches what I'd expect, but the code does the opposite.

3. Test coverage

This touches the rename gating logic which is exercised by tests/test_session_rename.py and adjacent tests — worth running pytest tests/test_session_rename.py -q and ideally adding a regression test for whatever specific scenario you hit (e.g. "rename UI opens on dblclick when X" so we don't regress later).

I'd hold off on merging until (1) is clarified — if the existing pointerup detection is indeed broken on some platform, the right fix is probably patching that handler, not adding a parallel ondblclick. (2) looks like a real bug regardless.