Loki Mode

Fixed

• Generated-PRD reuse honesty (closes the four honest-behavior gaps in the
  v7.8.1 staleness-aware reuse): the reuse disclosure now names the date and
  the --fresh-prd lever; a hand-edited generated PRD is detected
  (user_owned) and used as-is with its own disclosure, never overwritten or
  re-baselined; the incremental-update path also discloses --fresh-prd;
  reuse runs make zero re-analysis provider calls (proven end-to-end by a
  stub suite: byte-identical PRD on run 2).
• --fresh-prd (the flag named in the runtime disclosure) is now documented
  in loki start --help, wiki/CLI-Reference.md, and
  wiki/Environment-Variables.md alongside its aliases (--regen-prd,
  --regenerate-prd, --regen, LOKI_PRD_REGEN=1).
• The interactive pre-run prompt now also mentions the hand-edited
  (use-as-is) outcome, matching actual behavior.