Fatal crash on startup: cannot unmarshal number into sso_sync_with_provider (type bool)

[fs-bmedkouri]

Problem

The server authenticates successfully but crashes during user cache warmup with a JSON unmarshal error. The Slack API returns a number for Prefs.team.prefs.sso_sync_with_provider where the Go struct expects a bool.

Error

{"level":"info","message":"Authenticated to Slack"}
{"level":"info","message":"Authenticating with Slack API...","context":"console"}
{"level":"info","message":"Successfully authenticated with Slack","context":"console"}
{"level":"info","message":"Caching users collection...","context":"console"}
{"level":"error","message":"Failed to fetch client user boot","error":"json: cannot unmarshal number into Go struct field Prefs.team.prefs.sso_sync_with_provider of type bool"}
{"level":"error","message":"Failed to fetch users from Slack Connect","error":"json: cannot unmarshal number into Go struct field Prefs.team.prefs.sso_sync_with_provider of type bool"}
{"level":"fatal","message":"Error booting provider","context":"console","error":"json: cannot unmarshal number into Go struct field Prefs.team.prefs.sso_sync_with_provider of type bool"}

Stack trace

github.com/korotovsky/slack-mcp-server/pkg/provider.(*ApiProvider).GetSlackConnect
    /Users/runner/work/slack-mcp-server/slack-mcp-server/pkg/provider/api.go:1010
github.com/korotovsky/slack-mcp-server/pkg/provider.(*ApiProvider).refreshUsersInternal
    /Users/runner/work/slack-mcp-server/slack-mcp-server/pkg/provider/api.go:842
github.com/korotovsky/slack-mcp-server/pkg/provider.(*ApiProvider).RefreshUsers
    /Users/runner/work/slack-mcp-server/slack-mcp-server/pkg/provider/api.go:736
main.main.func1.newUsersWatcher.1
    /Users/runner/work/slack-mcp-server/slack-mcp-server/cmd/slack-mcp-server/main.go:175
main.main.func1
    /Users/runner/work/slack-mcp-server/slack-mcp-server/cmd/slack-mcp-server/main.go:75

Environment

• Package version: 1.2.3 (latest via npx -y slack-mcp-server)
• Platform: Windows (amd64), running via MCP client (stdio transport)
• Auth: Browser cookies (xoxc/xoxd)
• Workspace type: Standard workspace

Analysis

This is similar to the unmarshal bug fixed in #134 (slack-go/slack v0.17.1 → v0.17.3), but in a different code path. The Prefs struct in pkg/provider/edge/ likely has sso_sync_with_provider typed as bool, but the Slack API returns a numeric value (e.g., 0 or 1) for some workspaces.

Suggested fix

Change the sso_sync_with_provider field type in the Prefs struct to handle both bool and numeric values, or use a custom JSON unmarshaler. Alternatively, use json.Number or interface{} for fields in the prefs struct that may vary in type across workspaces.