release: 2.10.3: backup-reauth - the account password before a backup

Cut without asking, as the owner said on 2026-10-15. The full backup and a
domain's export ask for the signed-in user's account password under the
password change's limit; the import's file field is drawn as designed
(1888dce design, the code commit before this). go vet, go test (26
packages) and make e2e passed on the test server for that tree. No
migration, schema 12.

CHANGELOG [2.10.3]; pins in deploy/docker-compose.yml, README and the guide
(pin, build, the sample restore message); development's "from pin" and
row 35; roadmap row. No tag.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/development.md

@@ -107,7 +107,7 @@ than the default «meaningful step» rule in [§ Commits and release build](#com
 2. Git tag `vX.Y.Z` and publish the GitHub Release only on explicit request (see
    [§ Release image](#release-image)).
 
-**Planned version cuts** (from pin `2.10.2`; adjust if semver changes mid-track):
+**Planned version cuts** (from pin `2.10.3`; adjust if semver changes mid-track):
 
 | Stage | ID | Cut |
 |---|---|---|
@@ -145,6 +145,7 @@ than the default «meaningful step» rule in [§ Commits and release build](#com
 | 32 | inbound-upstream-result | `2.10.0` |
 | 33 | long, non-repeating queue ids | `2.10.1` (PATCH) |
 | 34 | phone-desktop-mode | `2.10.2` (PATCH) |
+| 35 | backup-reauth | `2.10.3` (PATCH) |
 
 Docs-only prep (checklists in plans, no product code) uses the same per-step
 commit rule but **no** version cut until the next product stage ships.