Add host-owned ASGI route registration

[dcaayushd]

Summary

Fixes #447.

Adds a public lifecycle split for host-owned ASGI integrations:

• Adds App.register_routes() to synchronously register the Teams messaging endpoint without starting a server or running async plugin init.
• Adds App.start_plugins() so hosts can run plugin on_init hooks later from their ASGI startup lifecycle.
• Returns a public HttpRoute route table from registration.
• Ships StarletteAdapter as part of microsoft_teams.apps.http instead of leaving it example-only.
• Updates host-owned FastAPI/Starlette examples and docs to use the new lifecycle.

Validation

./.venv/bin/python -m pytest packages/apps/tests packages/botbuilder/tests
./.venv/bin/python -m ruff check packages/apps/src/microsoft_teams/apps packages/apps/tests/test_app.py packages/apps/tests/test_http_server.py examples/a2a/src/main.py examples/http-adapters/src/fastapi_non_managed.py examples/http-adapters/src/starlette_echo.py examples/mcp-server/src/main.py
./.venv/bin/pyright packages/apps/src/microsoft_teams/apps packages/botbuilder/src/microsoft_teams/botbuilder/adapter.py examples/a2a/src/main.py examples/http-adapters/src/fastapi_non_managed.py examples/http-adapters/src/starlette_echo.py examples/mcp-server/src/main.py

[lilyydu]

Hey @dcaayushd ,

Thanks for jumping on this! This looks like we're headed in the right direction - though I don't have a strong pref towards shipping the StarletteAdapter as apart of apps - @heyitsaamir do you have any particular ops?

[Copilot]

Pull request overview

This PR implements a first-class “host-owned ASGI lifecycle” integration for the Teams Python SDK by splitting synchronous route registration from async plugin initialization, and by shipping a supported Starlette adapter.

Changes:

• Added App.register_routes() (sync) and App.start_plugins() (async) to support caller-owned ASGI app lifecycles while keeping plugin on_init decoupled from route contribution.
• Updated HttpServer.initialize() to return a public HttpRoute table and to expose HttpServer.routes.
• Promoted StarletteAdapter from example-only to a shipped adapter and updated docs/examples/tests accordingly.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/apps/src/microsoft_teams/apps/app.py	Adds lifecycle split (register_routes, start_plugins) and internal flags for initialization state.
packages/apps/src/microsoft_teams/apps/http/http_server.py	Returns and stores HttpRoute registrations; adds routes accessor.
packages/apps/src/microsoft_teams/apps/http/adapter.py	Introduces HttpRoute as a framework-agnostic route table entry.
packages/apps/src/microsoft_teams/apps/http/starlette_adapter.py	Ships Starlette-based adapter implementation with managed/non-managed lifecycle behavior.
packages/apps/src/microsoft_teams/apps/http/init.py	Exports HttpRoute and StarletteAdapter from the http package.
packages/apps/src/microsoft_teams/apps/init.py	Re-exports HttpRoute and StarletteAdapter at the apps package level.
packages/apps/tests/test_app.py	Adds coverage for the new register_routes() / start_plugins() lifecycle split.
packages/apps/tests/test_http_server.py	Updates HttpServer tests for route-table return + adds StarletteAdapter tests.
packages/apps/README.md	Documents the host-owned ASGI lifecycle pattern for FastAPI and Starlette hosts.
examples/http-adapters/src/fastapi_non_managed.py	Updates non-managed FastAPI example to use register_routes() + start_plugins().
examples/http-adapters/src/starlette_echo.py	Updates Starlette example to use shipped StarletteAdapter.
examples/http-adapters/README.md	Updates adapter examples documentation to reflect the new lifecycle split and shipped adapter.
examples/http-adapters/pyproject.toml	Updates example description to match shipped-adapter framing.
examples/mcp-server/src/main.py	Ensures Teams routes are registered before mounting MCP app (route priority), now via register_routes().
examples/a2a/src/main.py	Ensures Teams routes are registered synchronously before host-owned route table is finalized.

Comments suppressed due to low confidence (1)

packages/apps/src/microsoft_teams/apps/http/starlette_adapter.py:77

• StarletteAdapter.start() reuses an existing uvicorn.Server instance, which can cause start(port) to silently ignore a new port value and can prevent clean restarts after stop() (since stop() sets should_exit but the adapter keeps _server). Recreate the server when the requested port differs or when the previous server was asked to exit, so start() reliably honors its port argument.