fix: redirect resolver conversations from disabled personal workspaces to default org

[jpelletier1]

Summary

This PR fixes an edge case where resolver conversations (Slack and GitHub) would be created in disabled personal workspaces when HIDE_PERSONAL_WORKSPACES=true.

Problem

When personal workspaces are hidden and a user clicks "No Repository" in Slack (or triggers a GitHub resolver on an unclaimed git org), the conversation would fall back to the user's current_org_id. However, if the user hasn't logged in recently, their current_org_id might still point to their personal workspace, which is now disabled.

Solution

Added a fallback mechanism in both Slack and GitHub resolvers that:

1. Checks if HIDE_PERSONAL_WORKSPACES=true
2. Verifies if the user's current_org_id is their personal workspace (i.e., current_org_id == user_id)
3. If both conditions are true, redirects to the default org instead

Changes

Slack (enterprise/integrations/slack/slack_view.py)

• Added _get_fallback_org_for_no_repo() method
• Called in create_or_update_conversation() when resolved_org_id is None

GitHub (enterprise/integrations/github/github_view.py)

• Added _get_fallback_org_for_unclaimed() method
• Called in initialize_new_conversation() when resolved_org_id is None

Tests

• Added comprehensive unit tests for both Slack and GitHub fallback scenarios
• Tests cover: redirect to default org, no redirect when on team org, no redirect when personal workspaces enabled, error handling

Testing

The new behavior can be verified by:

1. Setting HIDE_PERSONAL_WORKSPACES=true
2. Having a user with current_org_id pointing to their personal workspace
3. Triggering a Slack resolver with "No Repository" or GitHub resolver on unclaimed org
4. Verifying the conversation is created in the default org, not the personal workspace

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This PR was created by an AI agent (OpenHands) on behalf of the user.

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Enterprise server image for this PR:

ghcr.io/openhands/enterprise-server:sha-1668cd4