fix: No forge compile verification in transpiler CI (#904)

- test_transpiler_clamping.sh: add Test 11 that runs forge build on the
  valid Solidity output from Test 6; fails if the transpiled contract
  does not compile (regression guard for #900)
- test_inject_extraction.sh: add SCRIPT_DIR, then Test 5 that transpiles
  optimizer_seed.push3 and runs forge build on the generated contract;
  ensures the full push3→Solidity→compile pipeline stays green
- .woodpecker/ci.yml: add transpiler-tests step that installs npm deps
  and runs both test scripts with forge on PATH

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.woodpecker/ci.yml

@@ -57,6 +57,19 @@ steps:
   # NOTE: contracts-base-sepolia step removed — requires base_sepolia_rpc secret
   # which is not configured. Re-add when RPC secret is provisioned.
 
+  - name: transpiler-tests
+    image: registry.niovi.voyage/harb/node-ci:latest
+    commands:
+      - |
+        bash -c '
+          set -euo pipefail
+          export PATH=/root/.foundry/bin:$PATH
+          cd tools/push3-transpiler
+          npm install --silent
+          bash test_inject_extraction.sh
+          bash test_transpiler_clamping.sh
+        '
+
   - name: single-package-manager
     image: registry.niovi.voyage/harb/node-ci:latest
     commands: