Replaces the single shared non-persisted composer state with a persisted draft system. Drafts are keyed by UUID, autosaved on debounced input, deleted on publish, and opened in a context-aware modal when the draft's parent post/group doesn't match the current composer location.

New modules

• types/draft.ts — PostDraft type capturing all composer state. DraftAttachment omits the non-serializable File field from NewAttachment. Includes toDraftAttachment/toNewAttachment converters.
• store/persisted/useDraftStore.ts — createPersistedTrackedStore holding Record<string, PostDraft> with saveDraft/removeDraft actions.
• store/non-persisted/modal/useDraftModalStore.ts — Controls the draft context-mismatch modal.
• components/Composer/DraftList.tsx — Renders saved drafts sorted by updatedAt, with delete and context-aware open (matching context → main modal, mismatch → dedicated draft modal).

Modified modules

• NewPublication — Generates a draft UUID on mount (draftId prop or new UUID). Autosaves via debounced useEffect (1s text, 2s attachments/audio/poll). Calls removeDraft in onCompleted.
• NewPost — Renders <DraftList> below the composer trigger.
• GlobalModals — Adds draft modal with DraftModalContent that hydrates all post stores from the draft via useEffect, then renders NewPublication with the draft's group/parent context.
• data/storage.ts — Adds DraftStore key.

Draft state captured

Post content, attachments (sans File), audio metadata (artist, title, cover), video thumbnail/duration, quoted post, parent post, group, content warning, poll config, collect action, license, and post rules.