Stability checkpoint Java — green icon + cosign fix + LICENSE + sonar tag fix

Achievements vs stable-v1.1.0 :
- Green homogeneous icon (radar arcs orange → green to match Spring color)
- README rewrite : 50+ → 8 badges + hiring TL;DR + 8-row 'What this proves
  for senior architect' matrix + URL fixes (benoit.besson → mirador1)
  + industrial onboarding framing
- TASKS.md created with SLO + README polish backlog
- BSD-3-Clause LICENSE
- SLO/SLA-as-code (Sloth) : 3 SLOs (availability 99%, latency p99, enrichment 99.5%)
  + slo.yaml + sla.md + wrap-as-prometheusrule.py + ADR-0058 cross-cutting
- CI fixes :
  - Tag all jobs macbook-local (was hitting SaaS quota)
  - sonar-analysis specifically tagged
  - cosign verify identity regex updated for new project URL
- Shared submodule SHA bumped (ADR-0058 + SLO PrometheusRules + dashboard +
  default-branch check + runner healthcheck)

Validation : main pipeline green (post-merge MR !202).