Fix release dry-run and record API 26/35 testing

[andre487]

Changes

Release dry-run failed with HTTP 404 when checking repository metadata: the GitHub API URL ended in a slash. Use the canonical endpoint and add a regression test.

Include the release testing report for the signed candidate on API 26 and 35, covering all 41 scenarios with explicit limits and evidence. The original live dry-run remains marked failed until the full corrected workflow is rerun.

Validation

• Python tests, Black and isort passed; the corrected metadata helper also passed against live GitHub.
• Signed Android candidate: 66 tests, lint and build checks passed.
• Emulator checks covered SMS/notification capture, deduplication, queues, upgrade from 0.0.4, recovery, privacy, authentication/TLS and a 15-minute foreground/background run on each API.

No version bump or release publication.