fix(slack): publish installable 1.0.2 settings compatibility release

[alexk-dev]

Summary

• fix Slack plugin settings deserialization when stored config contains the legacy configured field
• stop persisting computed configured back into plugin config on save
• publish golemcore/slack 1.0.2 so installed runtimes receive the fix via the registry

Root cause

The settings read path deserialized persisted plugin config directly into SlackPluginConfig. Older stored payloads already contained a UI/computed field named configured, but SlackPluginConfig did not ignore unknown fields. That caused 400 responses when opening or saving Slack settings.

Changes

• add @JsonIgnoreProperties(ignoreUnknown = true) to SlackPluginConfig
• add @JsonIgnore to isConfigured() so the computed flag is not written back into stored plugin config
• add a regression test for reading legacy config and saving normalized config without configured
• bump the Slack plugin release to 1.0.2

Verification

• mvn -pl golemcore/slack -am -Dtest=SlackPluginConfigServiceTest,SlackPluginConfigTest,SlackPluginSettingsContributorTest,SlackAdapterTest,SlackPlanApprovalAdapterTest,SlackConfirmationAdapterTest -Dsurefire.failIfNoSpecifiedTests=false test
• python3 scripts/plugins_repo.py validate