feat: expose watch expression tools

[hatayama]

Summary\n\n- add enable-watch, clear-watch, and get-watch-values with bounded histories, baseline evaluation, compile diagnostics, and typed evaluation errors\n- register the watch commands in the CLI catalog, preserve schema-driven help and completion, and add a field-for-field Go response contract\n- document watch expressions, raw pause-point values, per-Step evaluation, error history, and domain-reload lifetime in the source skill and regenerated copies\n\n## Validation\n\n- Unity compile: 0 errors, 0 warnings\n- targeted Watch EditMode tests: 14/14 passed\n- scripts/check-go-cli.sh: passed\n- CLI help exposes --expression, --id, and --max-history (1-100)\n- E2E with dist/darwin-arm64/uloop: baseline frame 846 grew to 846, 847, 848, 849 across three Editor Steps\n- a throwing expression recorded System.FormatException and its message while Step continued\n- compile/domain reload cleared the in-memory watch registry\n- no dedicated jumping-ball scene exists in this checkout, so the equivalent Update path in SimulateMouseDemoScene was used; no PATH-resolved uloop was used

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: cf6d7b57-e85a-4a4b-a217-46d69254cb11

📥 Commits

Reviewing files that changed from the base of the PR and between 6d7111e and ece8a86.

⛔ Files ignored due to path filters (8)

• Assets/Tests/Editor/UnityCLILoop.Tests.Editor.asmdef is excluded by none and included by none
• Assets/Tests/Editor/WatchResponseContractTests.cs.meta is excluded by none and included by none
• Assets/Tests/Editor/WatchToolTests.cs.meta is excluded by none and included by none
• Packages/src/Editor/FirstPartyTools/UnityCLILoop.FirstPartyTools.Editor.asmdef is excluded by none and included by none
• Packages/src/Editor/FirstPartyTools/Watch/AssemblyInfo.cs.meta is excluded by none and included by none
• Packages/src/Editor/FirstPartyTools/Watch/UnityCLILoop.FirstPartyTools.Watch.Editor.asmdef is excluded by none and included by none
• Packages/src/Editor/FirstPartyTools/Watch/UnityCLILoop.FirstPartyTools.Watch.Editor.asmdef.meta is excluded by none and included by none
• Packages/src/Editor/FirstPartyTools/Watch/WatchTools.cs.meta is excluded by none and included by none

📒 Files selected for processing (14)

• .agents/skills/uloop-pause-point/SKILL.md
• .claude/skills/uloop-pause-point/SKILL.md
• Assets/Tests/Editor/WatchResponseContractTests.cs
• Assets/Tests/Editor/WatchToolTests.cs
• Packages/src/Editor/CliOnlyTools~/PausePoint/Skill/SKILL.md
• Packages/src/Editor/FirstPartyTools/ExecuteDynamicCode/AssemblyInfo.cs
• Packages/src/Editor/FirstPartyTools/Watch/AssemblyInfo.cs
• Packages/src/Editor/FirstPartyTools/Watch/WatchTools.cs
• Packages/src/Editor/ToolContracts/UnityCliLoopConstants.cs
• cli/common/tools/default-tools.json
• cli/dispatcher/internal/dispatcher/help_test.go
• cli/project-runner/internal/projectrunner/watch_response_contract_test.go
• cli/project-runner/internal/projectrunner/watch_types.go
• tests/contracts/watch_response_contract.json

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📝 Walkthrough

Walkthrough

Added watch-expression CLI tools for registering, clearing, and retrieving expressions evaluated during paused Play Mode. The change includes editor monitoring, bounded history, response contracts across C# and Go, validation tests, shared fixtures, command help coverage, and documentation.

Changes

Watch expressions

Layer / File(s)	Summary
Watch command and response contracts Packages/src/Editor/ToolContracts/UnityCliLoopConstants.cs, Packages/src/Editor/FirstPartyTools/Watch/WatchTools.cs, cli/common/tools/default-tools.json	Adds watch command names, request schemas, response models, tool registrations, and default CLI schemas.
Watch execution and editor monitoring Packages/src/Editor/FirstPartyTools/Watch/WatchTools.cs, Packages/src/Editor/FirstPartyTools/.../AssemblyInfo.cs	Validates requests, compiles and registers expressions, manages bounded history, starts the editor monitor, and shapes success, failure, and compilation responses.
Cross-language response contract cli/project-runner/internal/projectrunner/watch_types.go, tests/contracts/watch_response_contract.json	Defines Go response DTOs and a shared JSON fixture for watch response field shapes.
Validation and usage documentation Assets/Tests/Editor/Watch*, cli/.../help_test.go, cli/.../watch_response_contract_test.go, .agents/skills/..., .claude/skills/..., Packages/src/Editor/CliOnlyTools~/...	Adds validation, empty-state, help, serialization-contract tests, and documentation for watch registration, evaluation, history, errors, and lifecycle behavior.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Sequence Diagram(s)

sequenceDiagram
  participant CLI
  participant EnableWatchTool
  participant WatchUseCase
  participant WatchExpressionCompiler
  participant WatchExpressionRegistry
  participant EditorUpdateMonitor
  CLI->>EnableWatchTool: enable-watch request
  EnableWatchTool->>WatchUseCase: ExecuteAsync(parameters)
  WatchUseCase->>WatchExpressionCompiler: Compile expression
  WatchUseCase->>WatchExpressionRegistry: Register watch with max history
  WatchUseCase->>EditorUpdateMonitor: Ensure monitor started
  EditorUpdateMonitor->>WatchExpressionRegistry: Evaluate watches on changed frame
  WatchExpressionRegistry-->>CLI: Watch history and errors

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🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 16.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: adding watch expression tools.
Description check	✅ Passed	The description matches the changeset and covers tools, docs, contracts, and validation.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/pause-point-watch-tools

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