fix(deploy): per-mode duration estimator handles cover/extend/edit/lyrics signatures

fix(deploy): align m7 with claude.md — models/<org>/<repo> layout + gpu estimator

feat(deploy): m7 — hf spaces readme + cache bootstrap + zerogpu decorator

feat(ui): m6 polish — in-memory history sidebar + _safe_call error wrapper

feat(post): wire separate stems / normalise / mp3 export buttons in output panel (m5 g2)

feat(ui): wire lyrics tab + cross-tab use-in-generate handoff (m4)

feat(ui): wire cover/extend/edit tabs into the sidebar layout (m3 e3+e4)

feat(ui): wire single-lora picker into generate tab (m2 d5)

feat(app): wire generate tab end-to-end to ace-step backend

fix(ui): replace gr.Tabs with sidebar nav per wireframes

chore(fmt): apply ruff format and remove unused import in conftest

feat(app): bootstrap gradio blocks with brutalist mono chrome