emrg: GUI session list & title bar unified format project/name|id

[argszero]

Summary

Host feedback rant 2026-08-20T17:48:07: unify the session display format across the GUI sidebar history list, the open-sessions list, and the session title bar — all now use project/name|id.

Changes (6 files, +47/−70)

1. sidebar.js — history list: removed the 今天/昨天/更早 time grouping; sessions sorted by last-active time (updated_at || created_at) descending; each item shows project/name|id where project = cwd basename, name = title (or empty), id = session_id.
2. sidebar.js — open-sessions list: same project/name|id format (entry.projectName + title, id always shown).
3. app.js — renderSessionHeader(): unified to project/name|id (was project/title(sid) or project/sid); project fallback now also derives from the session's own cwd basename before home.
4. i18n.js / utils.js — removed the now-unused util.group* keys and groupLabel() helper (orphan detection would flag them).
5. Tests — conv-list boot test no longer expects group labels; open-session item test asserts the unified project/name|id format (id always present).

Verification

• GUI: 252 tests = 245 pass + 7 integration fails (local-only by design, emrg: daemon single-instance via fixed-port bind exclusivity (rant 2026-08-19T08:05:21) #861)
• pytest full suite: 981 passed + 1 skipped, import + CLI OK

[argszero]

✅ LGTM — cycle 1 (6 files +47/−70: sidebar history list drops time grouping, sorts by last-active desc, unified project/name|id everywhere incl. header; orphan util.group* keys + groupLabel removed; tests updated to assert the new format; GUI 245 pass, test + test-windows CI PASS)

[argszero]

✅ LGTM — cycle 2 (independent re-review: head ad299bc unchanged; sidebar/header unified project/name|id, time-grouping removed, orphan keys cleaned; GUI 245 pass + pytest 981; test + test-windows CI PASS)

[argszero]

✅ LGTM — cycle 3 (re-review: head unchanged, GUI session/header project/name|id unified, time-grouping removed, orphan keys cleaned; GUI 245 pass + pytest 981; test + test-windows CI PASS, mergeable CLEAN)