fix: preserve skill isolation and tool result history

[RainYuY]

AgentScope-Java Version

2.0.1-SNAPSHOT

Description

Background

This PR fixes several correctness, compatibility, and session-isolation issues in the Harness skill runtime and tool-result eviction flow.

Previously:

• Fresh sessions could lose tool groups that were active when the agent was built.
• Explicitly persisted empty tool-group state could be mistaken for missing state.
• Static skill mode bypassed skill and visibility filters and lost access to lazily loaded skill resources.
• Concurrent sessions shared a mutable SkillCatalog, allowing one session to overwrite or observe another session's filtered skill view.
• WorkspaceSkillRepository could resolve skills using another concurrent session's active runtime context.
• Persisted sessions with an empty active-group list could not see load_skill_through_path after upgrading.
• Tool-result eviction modified canonical agent state but could leave the copied reasoning input unchanged.
• Reused tool-call IDs could overwrite previously evicted results.
• Cached eviction replacements could overwrite metadata or state rewritten by pre-reasoning hooks.
• Real tool output beginning with the eviction placeholder text could bypass eviction.

Changes

Session and toolkit state

• Capture the toolkit's initially active groups after agent construction.
• Apply those groups only when creating a genuinely new session.
• Preserve explicitly persisted empty active-group state.
• Distinguish a missing legacy toolkit_activeGroups key from a present but empty value.
• Preserve the complete RuntimeContext when merging toolkit-level execution context.

Skill runtime

• Use HarnessSkillMiddleware for both live and frozen repository modes.
• Freeze repository enumeration when dynamic skills are disabled while retaining per-request filtering.
• Apply SkillFilter and SkillVisibilityFilter before staging, prompt rendering, and catalog installation.
• Preserve the source repository association needed for lazy resource loading.
• Add RuntimeContextSkillRepository for repositories whose contents depend on the current request.
• Make WorkspaceSkillRepository enumerate skills using the supplied request context.
• Store SkillCatalog in the request-scoped RuntimeContext instead of a shared mutable reference.
• Resolve load_skill_through_path authorization from the tool call's runtime context.
• Register the skill loader as an ungrouped tool during agent construction so persisted sessions can continue to access it.
• Retain the previous public constructors and methods as deprecated compatibility overloads.

Tool-result eviction

• Evict oversized results from both canonical AgentState and the hook-modified ReasoningInput.
• Preserve hook deletions, rewrites, metadata, result state, message metadata, timestamps, and usage.
• Use content-addressed paths so reused tool-call IDs do not overwrite historical results.
• Include result text in the in-call eviction fingerprint.
• Cache only the generated placeholder instead of an entire ToolResultBlock.
• Mark evicted results with dedicated metadata instead of recognizing them by text prefix.
• Change the default eviction directory to the workspace-relative large_tool_results path.
• Update the English and Chinese memory documentation accordingly.

Compatibility

The following previously published APIs remain available as deprecated compatibility paths:

• SkillRuntime.currentCatalog()
• SkillRuntime.install(SkillCatalog, Toolkit)
• SkillLoadTool(AtomicReference<SkillCatalog>)

Context-bearing tool calls never fall back to the legacy shared catalog, preserving session isolation.

How to test

The focused core and Harness regression suite can be run with:

mvn -pl agentscope-harness -am \
  -Dtest=ReActAgentPerSessionStateTest,ToolExecutionContextIntegrationTest,ToolResultEvictionMiddlewareTest,HarnessSkillMiddlewareContextIsolationTest,WorkspaceSkillRepositoryTest,SkillRuntimeTest,SkillLoadToolFrontmatterViewTest,HarnessAgentDynamicHookBuilderTest \
  -Dsurefire.failIfNoSpecifiedTests=false \
  test

[codecov]

Codecov Report

❌ Patch coverage is 79.14439% with 39 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...cope/harness/agent/skill/runtime/SkillRuntime.java	65.38%	4 Missing and 5 partials ⚠️
...agent/middleware/ToolResultEvictionMiddleware.java	87.87%	6 Missing and 2 partials ⚠️
...ope/harness/agent/skill/runtime/SkillLoadTool.java	65.21%	5 Missing and 3 partials ⚠️
...rness/agent/middleware/HarnessSkillMiddleware.java	84.61%	1 Missing and 5 partials ⚠️
...va/io/agentscope/core/state/LegacyStateLoader.java	58.33%	3 Missing and 2 partials ⚠️
...e/src/main/java/io/agentscope/core/ReActAgent.java	92.30%	0 Missing and 1 partial ⚠️
...java/io/agentscope/harness/agent/HarnessAgent.java	80.00%	0 Missing and 1 partial ⚠️
.../harness/agent/skill/WorkspaceSkillRepository.java	50.00%	0 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

[RainYuY]

@chickenlj @jujn PTAL