Plugin Stuff Round 5

[lbedner]

No description provided.

[Copilot]

Pull request overview

This PR introduces runtime plugin discovery via Python entry points and wires plugin-provided Typer sub-apps into the main aegis CLI, enabling third-party plugins to extend both the plugin-spec layer and CLI surface.

Changes:

• Added aegis/core/plugin_discovery.py to discover PluginSpec and plugin CLI typer.Typer apps via the aegis.plugins / aegis.plugins.cli entry-point groups (with caching and error tolerance).
• Mounted discovered plugin Typer sub-apps into the main CLI in aegis/__main__.py.
• Added tests to pin discovery behavior and documented the entry-point groups in pyproject.toml.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
aegis/core/plugin_discovery.py	Implements entry-point based discovery for plugin specs and CLI sub-apps, including caching and stderr warnings.
aegis/__main__.py	Mounts discovered plugin Typer apps under aegis <plugin> ... at CLI initialization time.
tests/core/test_plugin_discovery.py	Adds unit tests covering discovery happy paths, error tolerance, collisions, and caching behavior.
pyproject.toml	Documents the plugin entry-point group contract via empty entry-point group tables.