fix(desktop): pass session profile through exportSession transcript reads

[Dusk1e]

What & why

Exporting a session from the cross-profile lists read its transcript without
the owning profile, so the request fell through to the local primary. A remote
(or non-default local) profile's rows live only on that profile's backend, so
the export 404'd, came back empty, or returned the wrong transcript.

exportSession now routes the transcript read to the session's owning profile
(params.profile ?? params.session?.profile ?? null). Both cross-profile
callsites — the command-center session list and the sidebar actions menu — pass
the profile through; current-profile search export is unaffected.

Reference

Parity follow-up to 9af54b2 (#39894, "make remote-profile sessions
first-class: resume, read, rename/archive/delete"), which established the
owner-profile read-routing invariant. exportSession was the remaining sibling
read path that still ignored it.

Tests

• tsc -b (type-check): clean
• eslint (changed files): clean
• New session-export.test.ts: 3/3 pass — owning-profile route · explicit-profile precedence · null (current-profile) fallback

[teknium1]

Thanks for the focused cross-profile export fix. This is already implemented on current main by commit 7a2d498b9 (fix(desktop): route profile session reads).

Automated hermes-sweeper review evidence:

• apps/desktop/src/lib/session-export.ts:35-36 resolves the explicit or owning session profile and passes it to getSessionMessages.
• apps/desktop/src/app/chat/sidebar/session-actions-menu.tsx:140 passes the sidebar row profile.
• apps/desktop/src/app/command-center/index.tsx:377 passes the session object, whose profile is resolved by the export helper.
• The implementation commit is contained in current main and is included by tag v2026.6.19.