Feat/add param dynamic tree select

[zyqzyq]

Description

Add dynamic-tree-select parameter type support to the plugin daemon, enabling tool/trigger/agent-strategy parameters to render hierarchical tree-structured options with dynamic loading. This is the plugin-daemon counterpart of the Dify main repo change in #35837.

Fixes langgenius/dify#35837

Type of Change

• Bug fix
• New feature
• Refactor
• Performance improvement
• Other

Essential Checklist

Testing

• I have tested the changes locally and confirmed they work as expected
• I have added unit tests where necessary and they pass successfully

Bug Fix (if applicable)

• I have used GitHub syntax to close the related issue (e.g., Fixes #123 or Closes #123)

Additional Information

Changes

1. pkg/entities/plugin_entities/constant.go — Add DYNAMIC_TREE_SELECT = "dynamic-tree-select" constant and Children []ParameterOption field to ParameterOption struct for hierarchical data support
2. pkg/entities/plugin_entities/tool_declaration.go — Add TOOL_PARAMETER_TYPE_DYNAMIC_TREE_SELECT constant and register it in isToolParameterType validator
3. pkg/entities/plugin_entities/trigger_declaration.go — Add EVENT_PARAMETER_TYPE_DYNAMIC_TREE_SELECT constant and register it in isEventParameterType validator
4. pkg/entities/plugin_entities/agent_declaration.go — Add AGENT_STRATEGY_PARAMETER_TYPE_DYNAMIC_TREE_SELECT constant and register it in isAgentStrategyParameterType validator
5. pkg/entities/requests/dynamic_select.go — Add Parent *string field to RequestDynamicParameterSelect for lazy-loading child nodes

Key design

• The new dynamic-tree-select type extends the existing dynamic-select pattern by adding a children field to ParameterOption, enabling recursive tree structures
• The optional parent field in the request allows plugins to implement lazy-loading of child nodes on demand
• The parameter type is registered across tool, trigger, and agent-strategy parameter systems for consistency

[gemini-code-assist]

Code Review

This pull request introduces the DYNAMIC_TREE_SELECT parameter type for agent strategies, tools, and triggers, while adding a Parent field to dynamic parameter select requests. The ParameterOption struct now supports hierarchical data via a recursive Children field. Feedback points out that EventParameterOption in trigger_declaration.go lacks a similar Children field, creating an inconsistency that prevents triggers from supporting hierarchical options.

[gemini-code-assist]

The dynamic-tree-select parameter type is being added to triggers, but the EventParameterOption struct (defined earlier in this file and used by EventParameter.Options) has not been updated to include a Children field. This is inconsistent with the changes made to ParameterOption in constant.go, which now supports hierarchy for tools and agent strategies. To ensure triggers can also support hierarchical options in their declarations, EventParameterOption should be updated to include a recursive Children field.