Prepare Wayfarer 1.9.9 release

[stef-k]

Prepare Wayfarer 1.9.9 with the address-edit correction (#565 / #567), cancelled enrichment and durable repair retries (#566 / #569), and restored isolated Quartz restart proof (#568 / #570). Update Version.props, dated release notes, version documentation/evidence, and the compiled-version assertion. Runtime implementation is unchanged in this release-preparation diff.

Audited source base: 6ebda61. The first-parent range from v1.9.8 contains exactly #567, #569, and #570. Released 1.9.8 notes are preserved, and one empty Unreleased section remains.

Migration notes: no added/changed migrations or snapshot since v1.9.8. Both migration trees are 690d44c6249db40da98ec6a2f81bed939a8984aa; latest migration remains 20260904100416_RetireLegacyRoutingAuthority. Preserve PostgreSQL and matching Data Protection keys during any later upgrade.

Validation:

• Independent release review: READY FOR RELEASE PR at a126b77; no reachable blockers.
• Fresh metadata check, 21 Python helper tests, and 26 compiled versioning tests passed. CLI emitted exactly Wayfarer 1.9.9 with empty stderr and exit 0.
• Diff/whitespace checks passed. Code Guard covered four selected files (three applicable); sole accepted REVIEW is the cohesive 854-line changelog. No FAIL/INCOMPLETE.
• Included PRs' exact-head test success independently verified. Historical product selections overlap and are not additive; broad suites were not repeated for metadata preparation.

Limits: browser interaction/screenshots remain unavailable; retry proof accelerates deadlines; restart proof mocks batch completion with bounded no-replay observation and persisted trigger absence. Original production inactivity remains unconfirmed. No full-suite-green claim.

This PR prepares release source only. Tag/GitHub release, deployable artifact identity/checksum, publication, and deployment remain separate steps. #505 stays open for backend deployment and subsequent Mobile coordination; its older version references are not current 1.9.9 evidence. Other open tracker issues remain deferred.

Merge gate: GitHub Actions test succeeds on the exact current PR head. Do not close #505.