feat(workers): Python skeleton + config + structlog

Plan 4 Phase A scaffolding. void-workers package at /workers/, sibling
of /lib/. pyproject.toml pins Python 3.12 with separate extras for
pdf / image / video / test.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

workers/README.md

@@ -0,0 +1,23 @@
+# void-workers
+
+Python ML ingest service alongside `void-server` (Node). Sibling of `lib/` in the void-v2 repo.
+
+## Local dev
+
+```bash
+cd workers
+python3.12 -m venv .venv
+. .venv/bin/activate
+pip install -e ".[all]"
+export DATABASE_URL="postgres://..."
+python -m void_workers.runner
+```
+
+## Tests
+
+```bash
+pip install -e ".[test,all]"
+DATABASE_URL="postgres://..." pytest -v
+```
+
+See `../docs/superpowers/plans/2026-06-01-void-v2-plan4-workers.md` for the full plan and `../docs/superpowers/specs/2026-06-01-void-v2-plan4-workers.md` for the design.