Release v0.51.227 — Release GU (stage-p11 — keep active New Chat visible in sidebar #3408)

[nesquena-hermes]

Release v0.51.227 — Release GU (stage-p11)

Single sidebar bug fix, screenshot-approved + invariant-verified by Nathan (Telegram, 2026-06-03).

Fixed

#3408 — keep the active New Chat visible in the sidebar (@AJV20). The sidebar intentionally filters inactive 0-message sessions, but that filter also hid the currently active blank chat until the user sent the first turn — so starting a New Chat could make the selected row vanish from the list. The active ephemeral session is now injected into the sidebar render rows (only when the server-side list omits it), while inactive empty sessions stay filtered as before. Starting a New Chat from a CLI-filtered sidebar also switches the source filter back to WebUI so the active chat isn't immediately hidden.

Review fixes (Codex, applied inline + regression tests)

• Search-pollution gate: _ensureActiveSessionRowPresent originally re-injected any active session after the search-merge, so an active conversation with messages that was correctly filtered out by a search query would pollute unrelated search results. Gated the re-injection to Number(activeRow.message_count||0) <= 0 so only the active freshly-created 0-message ephemeral chat is re-added; an active chat with messages stays filtered by search. Added a regression test asserting the gate (and that the old unconditional return is gone).

Live browser verification (the two invariants Nathan required)

Verified in a populated test environment via agent-browser CDP:

1. No stacking — clicking New Chat 3× keeps exactly ONE "Untitled" row (total rows stay 13, untitled stays 1); each new empty session replaces the prior active one rather than piling up.
2. Click-away disappears — navigating from an empty New Chat (nothing typed) to an existing conversation drops the row (13→12 rows, 1→0 Untitled); the unsent empty chat vanishes as soon as it's no longer active.

Gates

• Full suite: 7371 passed, 0 failures.
• Codex: SAFE TO SHIP — verified the search-pollution fix, the original fix(sidebar): keep active blank chat visible #3408 intent preserved (active 0-message chat survives the zero-message filter), inactive 0-message sessions don't leak, CLI→WebUI filter reset works.
• ESLint runtime gate + ruff forward gate: clean.

Closes #3408.
Co-authored-by: AJV20 AJV20@users.noreply.github.com