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/void_workers/__init__.py

@@ -0,0 +1 @@
+__version__ = "0.1.0"

workers/void_workers/config.py

@@ -0,0 +1,26 @@
+import os
+
+def env(name, default=None, required=False):
+    v = os.environ.get(name, default)
+    if required and v is None:
+        raise RuntimeError(f"env {name} is required")
+    return v
+
+def env_int(name, default):
+    return int(os.environ.get(name, default))
+
+DATABASE_URL = env("DATABASE_URL", required=True)
+BLOB_ROOT = env("BLOB_ROOT", "/var/lib/void/blobs")
+WHISPER_MODEL = env("WHISPER_MODEL", "small.en")
+WHISPER_CACHE = env("WHISPER_CACHE", "/var/lib/void/whisper-models")
+ALLOW_PRIVATE = env("VOID_INGEST_ALLOW_PRIVATE", "false") == "true"
+
+CONCURRENCY = {
+    "extract.pdf":      env_int("VOID_CONCURRENCY_EXTRACT_PDF", 2),
+    "extract.image":    env_int("VOID_CONCURRENCY_EXTRACT_IMAGE", 2),
+    "ingest.video":     env_int("VOID_CONCURRENCY_INGEST_VIDEO", 1),
+    "sync.source_doc":  env_int("VOID_CONCURRENCY_SYNC_SOURCE_DOC", 1),
+    "echo":             env_int("VOID_CONCURRENCY_ECHO", 1),
+}
+
+POLL_INTERVAL_MS = env_int("VOID_POLL_INTERVAL_MS", 1000)

workers/void_workers/log.py

@@ -0,0 +1,16 @@
+import logging
+import structlog
+
+def init():
+    structlog.configure(
+        processors=[
+            structlog.contextvars.merge_contextvars,
+            structlog.processors.add_log_level,
+            structlog.processors.TimeStamper(fmt="iso"),
+            structlog.processors.JSONRenderer(),
+        ],
+        wrapper_class=structlog.make_filtering_bound_logger(logging.INFO),
+    )
+    return structlog.get_logger()
+
+log = init()