[moonD4rk]

Phase 6, step 1 of 4 (RFC-012): lock today's Firefox and Safari output before their parsers move.

What

• New cmd fixtures, built in t.TempDir() like the Chromium one:
  • Firefox: a profiles dir with two profiles, each with its own key4.db, plus the non-profile entries a Linux profiles dir holds (profiles.ini, Crash Reports). Every category Firefox exports has records.
  • Safari: a ~/Library tree with the default profile and a titled and an untitled named profile from SafariTabs.db, the shared Downloads.plist, the container and legacy cookie jars, WebKit origin stores (first-party, partitioned, and one without localStorage), and both extension plists.
• New goldens from today's code: extract-firefox-{csv,json,cookie-editor} and extract-safari-{csv,json,cookie-editor}. As for Chromium, the cookie-editor golden holds only cookie.json.
• The goldens record today's bookmark bugs (Firefox folder always url, type empty, id 0; Safari IDs repeat per folder). Step 4 fixes them as a listed golden diff.
• The Safari test points HOME at the fixture, so no real login keychain is read and Safari exports no passwords here.
• TestExtractGolden, TestPipelineGolden, and the two new tests share one per-format golden loop. The file and SQLite helpers move from the Chromium fixture to fixture_test.go.

Test-only: no production code changes, and the existing goldens are unchanged.

Tests

• go test ./... and golangci-lint run pass locally; GOOS=linux and GOOS=windows vet pass.
• The new goldens are stable over repeated runs (-count=5).