feat(thread): track persistent goals across turns

[coygeek]

Summary

Add an optional goal for a thread that remains visible and tracks progress until completed, paused, edited, or cleared.

Problem to solve

T3 Code threads persist conversation and proposed plans, but users cannot state a durable outcome that the agent should keep working toward across follow-up turns or resumed sessions.

Proposed behavior

Let a user create a goal from the thread composer or command palette, show its current status above the composer, and let the user pause, resume, edit, or clear it. Persist the goal with the thread and include it in resumed and remote client state.

Acceptance criteria

• A user can create a goal without starting a second thread.
• The active goal and status are visible after navigation, reconnect, resume, and on supported web, desktop, and mobile clients.
• Pause, resume, edit, clear, and completion states are persisted; paused goals can be resumed, and clearing a goal visibly removes it.
• A goal is included in agent context only while active and is clearly distinguished from an ordinary prompt.
• No goal is created or changed by merely viewing a thread.

Affected area

Thread contracts and projections, orchestration turn context, composer and thread header surfaces in apps/web and apps/mobile, and desktop packaging of the shared client.

Non-goals

This request does not define autonomous scheduling, model selection, or a replacement for proposed implementation plans.

Alternatives considered

Keeping goals as pinned user messages does not provide reliable lifecycle state or a clear pause and resume contract.

Supporting context

Official OpenAI documentation describes persistent Goal mode with progress controls above the composer and pause, resume, edit, and clear actions: https://learn.chatgpt.com/docs/reference/slash-commands#available-slash-commands. The repository already has thread persistence and proposed-plan projections (apps/server/src/persistence/Services/ProjectionThreadProposedPlans.ts), so the requested outcome can be scoped to a thread-goal contract and UI lifecycle.

Related upstream work: Goal support discussion #6777 and native provider goals PR #11516. This proposal overlaps that work and offers acceptance criteria for the same user outcome.

Analysis basis: source inspection of T3 Code revision 9d4bb550a658. Statements about missing UI or contracts refer to that revision, not every provider-native capability or unmerged branch. This is a feature proposal based on source review, not a runtime bug reproduction.

[juliusmarminge]

Closing as a duplicate of #6777 — same persistent-goal / /goal outcome (create, track, pause, resume, clear across turns and clients).

In-flight implementation: #11516 (feat(goals): track native provider goals across clients). Acceptance criteria from this thread are useful context on that PR / #6777 rather than a separate Ideas track.