New documentation/controller/import-and-data-paths.md: the canonical import root
(and why it is NOT a registered StoragePath), the three data_paths roles, the
Fork-3 validation asymmetry, the class-driven copy rule, and the seven
invariants a future change must not break.
Capability map "File access via browser" — status DELIBERATELY UNCHANGED. The
drop-zone now has its own FileBrowser source and the app page carries a deep
link, both verified live, but nothing drove the FileBrowser HTTP UI (no browser
on DooPlex), so the row's standing "browse is exercised in no doc" caveat still
holds and PROVEN-LIVE remains unearned.
R-75 collapsed to its shipped one-liner. R-76 left open — this task does not fix
it, and nothing built here assumes an import/* directory stays 2775.
