chore: prepare Wayfarer 1.9.5 release

[stef-k]

Summary

• prepare Wayfarer backend version 1.9.5
• publish audited release notes for Fix deploy.sh production EF context selection #535, Priority: fix live Geoapify capability verification and actionable failure results #537, and Consolidate provider settings and separate Geoapify from legacy routing configuration #538
• document the routing-authority retirement migration and paired PostgreSQL/Data Protection rollback requirement
• align version documentation and exact runtime-version tests

Refs #505. This PR does not close the release/deployment authority issue.

Validation

• release helper tests: 21/21 passed
• versioning tests: 26/26 passed
• deployment-script context test: 1/1 passed
• release metadata check: passed
• Release build: passed with 0 warnings/errors
• previously completed candidate validation includes client, frontend, migration, Playwright, SpatiaLite, and backend suite evidence
• Code Guard: source guards passed; cumulative changelog document-size REVIEW accepted
• git diff --check main...HEAD: passed

Migration and rollback

The release adds 20260904100416_RetireLegacyRoutingAuthority. Back up PostgreSQL together with the complete matching Data Protection key ring before upgrading. Rolling back across this migration requires restoring the compatible pre-upgrade database and key ring; older binaries alone do not reverse it.

Boundaries

No tag, GitHub release, artifact publication, production deployment, provider contact, or Mobile release is included in this PR. #542 remains deferred non-blocking test maintenance. Python-managed deployment lifecycle work remains in #536.

Screenshots

Not applicable; this PR changes release metadata only. The underlying UI changes were validated in their reviewed feature PRs.