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/provider/tools/loaders/plugin.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import typing
+import traceback
+
+from .. import loader
+import langbot_plugin.api.entities.builtin.resource.tool as resource_tool
+
+
+# @loader.loader_class('plugin-tool-loader')
+class PluginToolLoader(loader.ToolLoader):
+    """插件工具加载器。
+
+    本加载器中不存储工具信息，仅负责从插件系统中获取工具信息。
+    """
+
+    async def get_tools(self, bound_plugins: list[str] | None = None) -> list[resource_tool.LLMTool]:
+        # 从插件系统获取工具（内容函数）
+        all_functions: list[resource_tool.LLMTool] = []
+
+        for tool in await self.ap.plugin_connector.list_tools(bound_plugins):
+            tool_obj = resource_tool.LLMTool(
+                name=tool.metadata.name,
+                human_desc=tool.metadata.description.en_US,
+                description=tool.spec['llm_prompt'],
+                parameters=tool.spec['parameters'],
+                func=lambda parameters: {},
+            )
+            all_functions.append(tool_obj)
+
+        return all_functions
+
+    async def has_tool(self, name: str) -> bool:
+        """检查工具是否存在"""
+        for tool in await self.ap.plugin_connector.list_tools():
+            if tool.metadata.name == name:
+                return True
+        return False
+
+    async def _get_tool(self, name: str) -> resource_tool.LLMTool:
+        for tool in await self.ap.plugin_connector.list_tools():
+            if tool.metadata.name == name:
+                return tool
+        return None
+
+    async def invoke_tool(self, name: str, parameters: dict) -> typing.Any:
+        try:
+            return await self.ap.plugin_connector.call_tool(name, parameters)
+        except Exception as e:
+            self.ap.logger.error(f'执行函数 {name} 时发生错误: {e}')
+            traceback.print_exc()
+            return f'error occurred when executing function {name}: {e}'
+
+    async def shutdown(self):
+        """关闭工具"""
+        pass