* Add installed_apps support to create_teams_chat action

Added optional installed_apps input to the create_teams_chat action, allowing
users to install apps (e.g. bots) into a chat at creation time via the
Microsoft Graph API's installedApps property.

This is required for bots to send messages in chats — they cannot be added as
regular members and must be installed as apps instead.

Changes:
- plugin.spec.yaml: Added installed_apps input (type []string) to create_teams_chat
- schema.py: Added INSTALLED_APPS constant and updated input JSON schema
- action.py: Passes installed_apps through to the Graph API client
- graph_api_client.py: Updated create_chat to format installedApps payload and
  handle the 202 Accepted async response (direct chat fetch with polling fallback)
- unit tests: Added test cases for installed_apps with oneOnOne and group chats
- test samples: Populated connection credentials across all test JSON files

* Prospector/Pylint fixes

MC0001 complexity (was 11) → Extracted _build_chat_payload from create_chat — now well under threshold
too-many-branches (was 19/15) → Split _handle_async_chat_creation into 5 focused methods: _try_direct_chat_fetch, _poll_chat_operation, _process_poll_response, _final_chat_fetch_or_partial, and the existing _extract_chat_id_from_location
unreachable code → Removed the duplicate raise PluginException block
import-outside-toplevel / reimported re → Removed the import re from inside _extract_chat_id_from_location (it's already at the top of the file)
Coverage fixes:

Added 10 new unit tests in TestGraphApiClientCreateChat that directly test the GraphApiClient methods (201, 202 direct fetch, 202 polling, payload format, error cases, location header parsing)
New code has 100% test coverage

* Add install_app action

New action - install_app:
- Accepts team_id or chat_id (mutually exclusive) and an app_id
- Calls POST /teams/{id}/installedApps or POST /chats/{id}/installedApps
- Validates that exactly one target is provided

* Refactor Install Apps Behavior

Connection
Added app_catalog_id (optional) — When configured, the bot automatically installs itself into chats on 403, eliminating manual steps
Bot Service (bot_service.py)
Constructor now accepts graph_client and app_catalog_id parameters
send_chat_message — on 403, if app_catalog_id is configured, auto-installs the bot in the chat via Graph API and retries the send
Refactored _send_activity into _send_activity + _send_activity_raw to allow inspecting the response status before handling
Graph API Client (graph_api_client.py)
create_chat — simplified back to synchronous-only (no more installed_apps param or 202 async handling)
Removed: _handle_async_chat_creation, _try_direct_chat_fetch, _poll_chat_operation, _process_poll_response, _final_chat_fetch_or_partial, _extract_chat_id_from_location, install_app_in_team
Kept: install_app_in_chat (used internally by bot service auto-install)
Actions
create_teams_chat — removed installed_apps input (redundant with connection-level auto-install)
install_app — removed entirely (action, schema, tests, sample)

* Update changelog

* Refactor Bot Install

bot_service.py — back to a clean, standalone service. No graph_client or app_catalog_id references. Just sends messages and raises PluginException on 403.
connection.py — stores app_catalog_id as a connection-level attribute (self.connection.app_catalog_id)
action.py
 — new _send_chat_message_with_auto_install method catches the 403 PluginException, checks if app_catalog_id is configured, calls self.connection.client.install_app_in_chat(), and retries the send.

* Update app cat usage

app_catalog_id now lives on GraphApiClient (as self.app_catalog_id)
install_app_in_chat(chat_id) no longer takes an app_id parameter — it uses the internally stored self.app_catalog_id
Connection passes app_catalog_id to GraphApiClient.__init__
The action code is now simplified

* Bump SDK to 6.6.0 and add enable_cache entry

* Set enable_cache to true.