v0.3.4

What's Changed

• docs(architecture): add ADR-0006 for library-first CLI parity by @3leapsdave in #100
• feat(reflow): expose adaptive concurrency substrate by @3leapsdave in #101
• feat(reflow): expose redaction helpers by @3leapsdave in #102
• feat(reflow): expose typed reflow records by @3leapsdave in #103
• feat(gcs): add slice 0 provider contract by @3leapsdave in #104
• feat(gcs): add slice 1 read provider substrate by @3leapsdave in #105
• feat(gcs): enable slice 2 read dispatch by @3leapsdave in #106
• feat(gcs): enable slice 3 write destinations by @3leapsdave in #107
• docs(testing): bring-your-own-bucket real-cloud integration by @3leapsdave in #108
• test(gcs): add opt-in real GCS lane by @3leapsdave in #109
• Harden reflow probe concurrency and cross-version checkpoint resume by @3leapsdave in #110
• Release prep: v0.3.4 (GCS provider docs + version bump) by @3leapsdave in #111

Full Changelog: v0.3.3...v0.3.4