refactor(shadow-testing): merge scripts/ into tests/, deduplicate docs, fix numbering

Merge scripts/shadow-testing/ into tests/shadow-testing/:
- Move fetch-l2-blocks.py to tests/shadow-testing/scripts/
- Move .env.example to tests/shadow-testing/.env.example
- Remove redundant scripts/shadow-testing/ directory entirely
  (setup.sh, import-production-data.sh, configs/ superseded by
   Makefile targets and 00-import-bundle-range.sh)

Deduplicate documentation:
- README.md: Slim down to ~100 lines (entry + quick start + index)
- docs/README.md → docs/GUIDE.md (full detailed guide)
- docs/QUICKSTART.md: deleted (content merged into README.md)
- AGENTS.md → docs/TROUBLESHOOTING.md (structured traps)
- Update all internal links to point to new names

Fix script numbering collision:
- 02-deploy-verifier.sh → 03-deploy-verifier.sh
- Shift all subsequent scripts (+1)
- Update Makefile references and internal script calls

Update root AGENTS.md cross-references.

Author: lispc

AGENTS.md

@@ -25,9 +25,9 @@ Follow the structured testing guide in [`docs/testing/openvm-upgrade-testing-gui
 For testing proof generation against **real mainnet production tasks** without interfering with the live system, use the **Shadow Coordinator** approach. This is significantly faster than a full shadow fork:
 
 - **Architecture**: Local coordinator (`:8390`) + local prover (GPU), fed by imported production task data.
-- **Docs**: [`tests/shadow-testing/docs/README.md`](tests/shadow-testing/docs/README.md) — full setup guide, troubleshooting, config reference.
-- **Quick Start**: [`tests/shadow-testing/docs/QUICKSTART.md`](tests/shadow-testing/docs/QUICKSTART.md)
-- **Automation**: [`tests/shadow-testing/scripts/setup.sh`](tests/shadow-testing/scripts/setup.sh) — one-command setup for postgres, coordinator, and prover.
+- **Docs**: [`tests/shadow-testing/docs/GUIDE.md`](tests/shadow-testing/docs/GUIDE.md) — full setup guide, troubleshooting, config reference.
+- **Quick Start**: [`tests/shadow-testing/README.md`](tests/shadow-testing/README.md)
+- **Automation**: [`tests/shadow-testing/Makefile`](tests/shadow-testing/Makefile) — Makefile targets for Docker and bare-metal shadow fork testing.
 
 Key hard-won rules:
 - **L2 RPC for coordinator task generation** (must support `debug_executionWitness`):
@@ -201,7 +201,8 @@ make coordinator_setup
 | [`docs/prover-coordinator-overview.md`](docs/prover-coordinator-overview.md) | Architecture, data flow, component relationships, common operations |
 | [`docs/testing/openvm-upgrade-testing-guide.md`](docs/testing/openvm-upgrade-testing-guide.md) | Step-by-step testing checklist after OpenVM / zkvm-prover upgrades |
 | [`docs/testing/docker-compose-e2e-guide.md`](docs/testing/docker-compose-e2e-guide.md) | Production-like E2E testing with Docker Compose + Coordinator Proxy |
-| [`tests/shadow-testing/docs/README.md`](tests/shadow-testing/docs/README.md) | Shadow coordinator + local prover setup for production task replay |
+| [`tests/shadow-testing/docs/GUIDE.md`](tests/shadow-testing/docs/GUIDE.md) | Shadow coordinator + local prover setup for production task replay |
 | [`tests/shadow-testing/docs/LESSONS_LEARNED.md`](tests/shadow-testing/docs/LESSONS_LEARNED.md) | Hard-won debugging knowledge from past shadow tests (read before experimenting) |
-| [`tests/shadow-testing/docs/QUICKSTART.md`](tests/shadow-testing/docs/QUICKSTART.md) | Quick reference for common shadow testing commands |
+| [`tests/shadow-testing/docs/TROUBLESHOOTING.md`](tests/shadow-testing/docs/TROUBLESHOOTING.md) | Structured pitfalls and agent checklists for shadow testing |
+| [`tests/shadow-testing/README.md`](tests/shadow-testing/README.md) | Quick reference for common shadow testing commands |
 | [`docs/testing_reports/openvm-v1.6.0-guest-v0.8.0-May19.md`](docs/testing_reports/openvm-v1.6.0-guest-v0.8.0-May19.md) | Test report for PR #1783 (OpenVM 1.6.0, guest v0.8.0) |