Stability checkpoint — dependency freshness sweep (18 build/lib bumps)

- chore(deps): freshness sweep — 18 build/lib property bumps
- docs(tasks): record upstream GitLab bug #605371 for compat-schedule
- docs(tasks): compat-schedule 0-job confirmed GitLab bug

CI :
- OK Main pipeline #1186 green — https://gitlab.com/iris-7/iris-service-java/-/pipelines/2665135999
  Covers compat matrix (SB3/SB4 x Java 17/21), integration-test,
  owasp-dependency-check, build-jar, build-native, terraform-plan +
  terraform-apply (GKE deploy), smoke-test. All green.
- OK Pre-merge MR !321 pipeline #1184 green — https://gitlab.com/iris-7/iris-service-java/-/merge_requests/321
- OK owasp-dependency-check : green post-bump — no CVE introduced by the 18 updates.

Local test pass :
- SKIP ./mvnw verify — N/A : the full compat matrix + integration already ran
  green in main pipeline #1186 ; re-running locally would only duplicate CI for
  a deps-only, in-range property change.
- SKIP bin/dev/stability-check.sh — N/A : deps-only rev, no source / arch / root
  hygiene change to re-audit.

Regression check vs stable-v1.2.25 :
- OK No known limitation regressed ; the bumps are in-range property updates only.

- SKIP N/A — no AI / MCP change this rev.

- owasp-dependency-check green post-bump — the 18 property updates introduce no
  new CVE.

- SKIP N/A — deps maintenance only, no domain / endpoint change.

- terraform-plan + terraform-apply ran green in #1186 — the GKE deploy path is
  exercised end-to-end at this checkpoint.

- SKIP N/A — no observability change this rev.

- 18 build/lib property bumps keep the dependency tree fresh ; full unit +
  integration suite green in CI.

- Compat matrix SB3/SB4 x Java 17/21 green on main ; no pipeline definition change.

- SKIP N/A — no architectural / ADR change.

- SKIP N/A — backend repo.

- Freshness sweep reduces upgrade debt ahead of the next feature wave.

- compat-schedule scheduled pipeline runs 0 jobs — confirmed UPSTREAM GitLab bug
  #605371 (not our config). Tracked in TASKS.md ; recheck when GitLab ships a fix.

- Next functional feature wave, or a major-version dependency bump that requires
  code changes (held out of this in-range sweep).