preact 07-combined: multi-view shell + editable Profile + Tasks CRUD

The synthesis stage. Combines stage 5's shell + discovery with stage 6's
read/write loop, plus inline-editable Profile with WebID-doc-preserving
write-back.

  - useEditableProfile() owns the FULL fetched JSON-LD doc, not just a
    flattened view. Edits target the matching subject node and PUT the
    whole doc — pod-only fields (oidcIssuer, storage, sameAs, ldp:inbox)
    survive intact.
  - readField/writeField walk a predicate alias list, reusing whatever
    key the doc already has (foaf:name vs http://xmlns.com/foaf/0.1/name)
    and falling back to a canonical predicate (vcard:note for bio,
    foaf:* for the rest) when adding a brand-new field.
  - TasksView ports the full CRUD from stage 6.
  - Per-view save status: '… saving' / '\u2713 saved to pod' / '\u26a0 error'.

Real Solid editor in one HTML file, multi-view, persistent.

Author: melvincarvalho