Function buildSessionExperienceContext

src/views/SessionDistill.tsx:174–204

(
    workspace: { id: string; displayName: string },
    threads: SessionThread[],
)

 * Returns `null` when `threads` is empty.
 */
export function buildSessionExperienceContext(
    workspace: { id: string; displayName: string },
    threads: SessionThread[],
): BuildSessionResult | null {
    if (!threads.length) return null;

    const { trimmedThreads, notes } = trimToBudget(threads, SESSION_EVENT_BUDGET);

    const payload: SessionExperienceContext = {
        context_id: workspace.id,
        workspace_id: workspace.id,
        workspace_name: workspace.displayName,
        threads: trimmedThreads.map(t => ({
            thread_id: t.thread_id,
            events: t.events,
        })),
        ...(notes.length ? { payload_notes: notes } : {}),
    };

    const trimmedStepCount = trimmedThreads.reduce(
        (acc, t) => acc + t.events.filter(e => e.type === 'create_table').length,
        0,
    );

    return {
        payload,
        threads: trimmedThreads,
        stats: { threadCount: trimmedThreads.length, stepCount: trimmedStepCount },
        notes,
    };
}

/** JSON-byte size of an events array (used for budgeting). */
function eventsByteSize(events: Array<Record<string, any>>): number {