chore: Add PyPI package support for uvx/pip installation (#1764)

* Initial plan

* Add package structure and resource path utilities

- Created langbot/ package with __init__.py and __main__.py entry point
- Added paths utility to find frontend and resource files from package installation
- Updated config loading to use resource paths
- Updated frontend serving to use resource paths
- Added MANIFEST.in for package data inclusion
- Updated pyproject.toml with build system and entry points

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* Add PyPI publishing workflow and update license

- Created GitHub Actions workflow to build frontend and publish to PyPI
- Added license field to pyproject.toml to fix deprecation warning
- Updated .gitignore to exclude build artifacts
- Tested package building successfully

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* Add PyPI installation documentation

- Created PYPI_INSTALLATION.md with detailed installation and usage instructions
- Updated README.md to feature uvx/pip installation as recommended method
- Updated README_EN.md with same changes for English documentation

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* Address code review feedback

- Made package-data configuration more specific to langbot package only
- Improved path detection with caching to avoid repeated file I/O
- Removed sys.path searching which was incorrect for package data
- Removed interactive input() call for non-interactive environment compatibility
- Simplified error messages for version check

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* Fix code review issues

- Use specific exception types instead of bare except
- Fix misleading comments about directory levels
- Remove redundant existence check before makedirs with exist_ok=True
- Use context manager for file opening to ensure proper cleanup

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* Simplify package configuration and document behavioral differences

- Removed redundant package-data configuration, relying on MANIFEST.in
- Added documentation about behavioral differences between package and source installation
- Clarified that include-package-data=true uses MANIFEST.in for data files

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

* chore: update pyproject.toml

* chore: try pack templates in langbot/

* chore: update

* chore: update

* chore: update

* chore: update

* chore: update

* chore: adjust dir structure

* chore: fix imports

* fix: read default-pipeline-config.json

* fix: read default-pipeline-config.json

* fix: tests

* ci: publish pypi

* chore: bump version 4.6.0-beta.1 for testing

* chore: add templates/**

* fix: send adapters and requesters icons

* chore: bump version 4.6.0b2 for testing

* chore: add platform field for docker-compose.yaml

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>
Co-authored-by: Junyan Qin <rockchinq@gmail.com>

src/langbot/pkg/api/http/controller/groups/files.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import quart
+import mimetypes
+import uuid
+import asyncio
+
+import quart.datastructures
+
+from .. import group
+
+
+@group.group_class('files', '/api/v1/files')
+class FilesRouterGroup(group.RouterGroup):
+    async def initialize(self) -> None:
+        @self.route('/image/<image_key>', methods=['GET'], auth_type=group.AuthType.NONE)
+        async def _(image_key: str) -> quart.Response:
+            if '/' in image_key or '\\' in image_key:
+                return quart.Response(status=404)
+
+            if not await self.ap.storage_mgr.storage_provider.exists(image_key):
+                return quart.Response(status=404)
+
+            image_bytes = await self.ap.storage_mgr.storage_provider.load(image_key)
+            mime_type = mimetypes.guess_type(image_key)[0]
+            if mime_type is None:
+                mime_type = 'image/jpeg'
+
+            return quart.Response(image_bytes, mimetype=mime_type)
+
+        @self.route('/documents', methods=['POST'], auth_type=group.AuthType.USER_TOKEN)
+        async def _() -> quart.Response:
+            request = quart.request
+
+            # Check file size limit before reading the file
+            content_length = request.content_length
+            if content_length and content_length > group.MAX_FILE_SIZE:
+                return self.fail(400, 'File size exceeds 10MB limit. Please split large files into smaller parts.')
+
+            # get file bytes from 'file'
+            files = await request.files
+            if 'file' not in files:
+                return self.fail(400, 'No file provided in request')
+
+            file = files['file']
+            assert isinstance(file, quart.datastructures.FileStorage)
+
+            file_bytes = await asyncio.to_thread(file.stream.read)
+
+            # Double-check actual file size after reading
+            if len(file_bytes) > group.MAX_FILE_SIZE:
+                return self.fail(400, 'File size exceeds 10MB limit. Please split large files into smaller parts.')
+
+            # Split filename and extension properly
+            if '.' in file.filename:
+                file_name, extension = file.filename.rsplit('.', 1)
+            else:
+                file_name = file.filename
+                extension = ''
+
+            # check if file name contains '/' or '\'
+            if '/' in file_name or '\\' in file_name:
+                return self.fail(400, 'File name contains invalid characters')
+
+            file_key = file_name + '_' + str(uuid.uuid4())[:8]
+            if extension:
+                file_key += '.' + extension
+
+            # save file to storage
+            await self.ap.storage_mgr.storage_provider.save(file_key, file_bytes)
+            return self.success(
+                data={
+                    'file_id': file_key,
+                }
+            )