feat(slackbot): add slack-search MCP for community thread search (#1270)

* revert: remove snippet upload feature (PRs #1262, #1263, #1265)

Reverting the Slack snippet upload feature as it doesn't create proper
snippets with line numbers. The Slack API behavior doesn't match
documentation. Will revisit later.

This reverts:
- bec525b fix(slackbot): pass snippet_type to create proper Slack code snippets (#1265)
- e3558f9 fix(slackbot): use files.upload for actual Slack snippets (#1263)
- 08ee978 feat(slackbot): upload long code blocks as Slack snippets (#1262)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* feat(slackbot): add slack-search MCP for community thread search

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: zzstoatzz

examples/slackbot/src/slackbot/core.py

@@ -12,6 +12,7 @@
 from prefect.logging.loggers import get_logger
 from prefect.variables import Variable
 from pydantic_ai import Agent, RunContext
+from pydantic_ai.mcp import MCPServerHTTP
 from pydantic_ai.messages import ModelMessage, ModelMessagesTypeAdapter
 from pydantic_ai.models import KnownModelName, Model
 from pydantic_ai.models.anthropic import AnthropicModel
@@ -46,6 +47,10 @@
 
 GITHUB_API_TOKEN = Secret.load(settings.github_token_secret_name, _sync=True).get()
 
+slack_search_mcp = MCPServerHTTP(
+    url="https://marvin-slack-thread-assets.fastmcp.app/mcp",
+)
+
 logger = get_logger(__name__)
 
 
@@ -186,6 +191,7 @@ def create_agent(
             check_cli_command,  # verify CLI commands before suggesting them
             get_latest_prefect_release_notes,  # get the latest release notes for Prefect
         ],
+        toolsets=[slack_search_mcp],  # search Prefect community Slack threads
         deps_type=UserContext,
     )