fix: missing sawMessage init in accumulator literal; add pre-commit port typecheck hook

The CI port job's tsc --noEmit caught SessionEventAccumulator literals not
initializing the new sawMessage field (tests don't typecheck, so bun test
was green). Add a committed .githooks/pre-commit that mirrors the CI port
job — regenerate the port into a temp dir and tsc --noEmit it — so this
class of error fails at commit time, not in CI.

README.md

@@ -202,6 +202,21 @@ pygienium/
 └─ agents/                 ← scanner.md  fixer.md  deep-modules.md  defensive-guards.md
 ```
 
+## Development
+
+The omp port at `~/.omp/agent/extensions/pygienium` is regenerated **only by CI
+on push** (`.gitea/workflows/port-to-omp.yml`) — never by hand.
+
+The source repo's own `tsconfig.json` extends the host harness tsconfig, so the
+reliable typecheck target is the regenerated port (self-contained tsconfig +
+pinned `@oh-my-pi` SDK devDependency). A committed pre-commit hook runs exactly
+what CI runs — regenerate the port into a temp dir and `tsc --noEmit` it — and
+fails the commit on any error:
+
+```sh
+git config core.hooksPath .githooks
+```
+
 ## License
 
 MIT