sync(receiptwitness): copy latest standalone code to monorepo

Syncs receiptwitness standalone repo code into monorepo subdirectory.
Includes email parsing, notifications, queue, and worker modules.
Keeps monorepo Dockerfile (uses local common/).

Co-Authored-By: Paperclip <noreply@paperclip.ing>

receiptwitness/pyproject.toml

@@ -14,11 +14,13 @@ dependencies = [
     "cryptography>=42.0,<44.0",
     "fastapi>=0.115,<1.0",
     "uvicorn[standard]>=0.30,<1.0",
+    "beautifulsoup4>=4.12,<5.0",
     "redis>=5.0,<6.0",
     "pydantic>=2.0,<3.0",
     "pydantic-settings>=2.0,<3.0",
     "sqlalchemy[asyncio]>=2.0,<3.0",
     "asyncpg>=0.29,<1.0",
+    "resend>=2.0",
 ]
 
 [project.optional-dependencies]
@@ -27,6 +29,9 @@ dev = [
     "pytest-asyncio>=0.23",
     "ruff>=0.3",
     "pytest-cov>=5.0",
+    "fakeredis[aioredis]>=2.20",
+    "httpx>=0.27",
+    "python-multipart>=0.0.9",
 ]
 
 [tool.hatch.build.targets.wheel]