Branch menu (list/switch) for macOS+iOS shared chat via sessions.branches.*;
rewind/fork/switch gated on run activity and pending outbox work through a
durable session-mutation lease; outbox rows carry branch-epoch ownership with
local-only flush checks, atomic confirm/park transitions, attempt-versioned
delivery callbacks, fresh retry identity for possibly-accepted rows, and
epoch-guarded branch evidence; 21-locale native translations for new strings.
* feat(clients): gateway session groups, batch operations, session inspector, and new-session options
* chore(i18n): translate session management strings and regenerate catalogs
* chore(i18n): complete translation artifacts for session management strings
* fix(clients): fail closed when a transport cannot honor agent or base-ref session options
* fix(clients): authoritative agent identity for new-session parents and revision-keyed sidebar group refresh
* fix(clients): refetch session groups on remote catalog events and correct Swedish repository-root translation
* fix(clients): resilient new-session popover, revision-keyed group manager, and popover string translations
* fix(clients): scope reset fallback to plain new-session requests and revision-key the inspector groups
* fix(clients): reject empty agent catalogs and refresh sessions on remote group events
* refactor(clients): drop unused agents fetch wrapper and runtime memberwise init flagged by periphery
* chore(i18n): realign locale artifacts after rebase onto model-controls main
* chore(clients): split session creation into the session-actions extension and realign i18n after ask-user main rebase
* chore(i18n): resync derived artifacts after question-card main rebase
* feat(clients): provider-grouped model picker with fast, verbosity, and inherited-thinking controls
* chore(i18n): translate model-control strings and regenerate platform catalogs
* feat(clients): inherited-default restore for fast mode and verbosity controls
* fix(clients): preserve control state in thinking snapshots and persist inherited verbosity
* chore(i18n): resync native inventory after rebase onto message-reader main
* chore(i18n): realign locale artifacts after rebase onto message-reader main
* refactor(clients): drop superseded fast-mode accessors and picker convenience flagged by periphery
* chore(i18n): resync inventory line refs after dead-code removal
