refactor(modules): remove thin-composition layer; rewrite all module READMEs

The L2 thin-composition layer (composition.json + contract_resolver.py +
contract schema + sample contracts) has been removed completely. The
implementation was unsatisfactory and is deferred for a later redesign.

- Delete: composition.json x2, contract_resolver.py, contracts/ x2,
  contract.schema.json
- Patch: run_platform.sh now loads a pre-existing IR instance instead of
  resolving a contract (the downstream adapter/checkov/confidence/outbox
  pipeline is unchanged)
- Prune: L2 entries removed from registry.json (L1 entries unchanged)
- Rewrite: all 7 L1 module READMEs in plain language (no jargon), each
  with Resources/Inputs/Outputs/Usage/Compliance-extension-points/Versioning
  sections derived from interface.json
- Add: 2 L2 placeholder READMEs noting the composition is under redesign
- Add: modules-ir/README.md catalog index + README-TEMPLATE.md

---ci---
project: acdl
phase: 17
milestone: v1.3
status: execute
---/ci---

modules-ir/registry.json

@@ -47,19 +47,5 @@
       "published_at": "2026-07-21T21:30:00Z",
       "deprecated": false
     }
-  },
-  "l2-static-asset": {
-    "1.0.0": {
-      "composition": "modules-ir/l2/l2-static-asset/composition.json",
-      "published_at": "2026-07-21T19:30:00Z",
-      "deprecated": false
-    }
-  },
-  "l2-microservice": {
-    "1.0.0": {
-      "composition": "modules-ir/l2/l2-microservice/composition.json",
-      "published_at": "2026-07-21T22:00:00Z",
-      "deprecated": false
-    }
   }
 }