refactor: rename the application package to docsgpt

The backend import package is now docsgpt, the name it will carry on PyPI;
application was far too generic to install into anyone's site-packages.
git mv plus a mechanical rewrite of every import, dotted string and path
reference: 734 Python files, the compose files, Dockerfile, workflows, docs,
setup scripts, devcontainer, k8s manifests, vscode config, pytest and coverage
config, .gitignore. Behaviour is unchanged.

Kept for one release:
- A top-level application package whose meta-path finder resolves
  application.x.y to the already-imported docsgpt.x.y object, so old imports
  and entry points (celery -A application.app.celery,
  uvicorn application.asgi:asgi_app) keep working with a FutureWarning.
- Celery registers every application.* task name as an alias of its
  docsgpt.* task on start-up, so messages queued by the previous release still
  run. The redbeat key prefix moves to redbeat:docsgpt:v2: so schedule entries
  the previous release wrote are left unread instead of firing twice.

The backend image builds from the repository root (docker build -f
docsgpt/Dockerfile .) so it can ship the alias package; a root .dockerignore
allow-lists docsgpt/ and application/ and keeps caches, local data, .env
files, the sample index files and the Dockerfile out. Compose and the image
workflows point at the new context.

docsgpt/parser/schema/__init__.py

@@ -0,0 +1 @@
+

docsgpt/parser/schema/base.py

@@ -0,0 +1,34 @@
+"""Base schema for readers."""
+from dataclasses import dataclass
+
+from docsgpt.parser.schema.schema import BaseDocument
+from docsgpt.vectorstore.document_class import Document as VectorDocument
+
+
+@dataclass
+class Document(BaseDocument):
+    """Generic interface for a data document.
+
+    This document connects to data sources.
+
+    """
+
+    def __post_init__(self) -> None:
+        """Post init."""
+        if self.text is None:
+            raise ValueError("text field not set.")
+
+    @classmethod
+    def get_type(cls) -> str:
+        """Get Document type."""
+        return "Document"
+
+    def to_vector_format(self) -> VectorDocument:
+        """Convert struct to the page_content/metadata shape vector stores take."""
+        metadata = self.extra_info or {}
+        return VectorDocument(page_content=self.text, metadata=metadata)
+
+    @classmethod
+    def from_vector_format(cls, doc: VectorDocument) -> "Document":
+        """Convert struct from the vector-store document shape."""
+        return cls(text=doc.page_content, extra_info=doc.metadata)

docsgpt/parser/schema/schema.py

@@ -0,0 +1,64 @@
+"""Base schema for data structures."""
+from abc import abstractmethod
+from dataclasses import dataclass
+from typing import Any, Dict, List, Optional
+
+from dataclasses_json import DataClassJsonMixin
+
+
+@dataclass
+class BaseDocument(DataClassJsonMixin):
+    """Base document.
+
+    Generic abstract interfaces that captures both index structs
+    as well as documents.
+
+    """
+
+    # TODO: consolidate fields from Document/IndexStruct into base class
+    text: Optional[str] = None
+    doc_id: Optional[str] = None
+    embedding: Optional[List[float]] = None
+
+    # extra fields
+    extra_info: Optional[Dict[str, Any]] = None
+
+    @classmethod
+    @abstractmethod
+    def get_type(cls) -> str:
+        """Get Document type."""
+
+    def get_text(self) -> str:
+        """Get text."""
+        if self.text is None:
+            raise ValueError("text field not set.")
+        return self.text
+
+    def get_doc_id(self) -> str:
+        """Get doc_id."""
+        if self.doc_id is None:
+            raise ValueError("doc_id not set.")
+        return self.doc_id
+
+    @property
+    def is_doc_id_none(self) -> bool:
+        """Check if doc_id is None."""
+        return self.doc_id is None
+
+    def get_embedding(self) -> List[float]:
+        """Get embedding.
+
+        Errors if embedding is None.
+
+        """
+        if self.embedding is None:
+            raise ValueError("embedding not set.")
+        return self.embedding
+
+    @property
+    def extra_info_str(self) -> Optional[str]:
+        """Extra info string."""
+        if self.extra_info is None:
+            return None
+
+        return "\n".join([f"{k}: {str(v)}" for k, v in self.extra_info.items()])