[FEATURE] Epic: gallery delivery & multi-photographer improvements

[Luca-Timo]

Umbrella for a batch of gallery/delivery feature ideas — parked, no timeline. Motivated by real photographer workflows (multi-shooter events, richer client proofing, editing-tool integration). Each item ships independently as its own PR/release line.

Not in scope: card payments / print store (tracked separately). CRM/accounting suite is unaffected.

Sub-features

• Multi-photographer "festival" upload — [FEATURE] Multi-photographer "festival" upload (scoped role + attribution + curation) #743
• Frame-level proofing (per-image comments + approve/reject) — [FEATURE] Frame-level proofing: per-image comments + approve/reject #744
• Lightroom round-trip (re-import approved selections) — [FEATURE] Lightroom round-trip: re-import client-approved selections #745
• Client-activity notifications — [FEATURE] Client-activity notifications (gallery opened / favorited / downloaded) #746
• Team workspaces / creative-team roles — [FEATURE] Team workspaces / creative-team roles #747
• Cloud-storage source ingestion (nice-to-have) — [FEATURE] Cloud-storage source ingestion (Dropbox) — nice-to-have #748

Rough priority (effort-adjusted)

notifications (S) → frame-level proofing (L, high value) → festival + team roles (L) → Lightroom round-trip (L) → cloud ingestion (nice-to-have)