feat(vscode): open agent-created plans

[marius-kilocode]

What Problem This Solves

Agents can create plan files without giving the user an immediate way to review them in the editor.

Why This Change Was Made

Add a VS Code-only open_plan tool. Completed tool events reuse the existing file-opening bridge, so both the sidebar and Agent Manager document viewer can open the saved plan.

User Impact

Plan-mode agents are instructed to open the plan before handing off with plan_exit. Code-mode agents can call open_plan when a user requests a Markdown plan. CLI behavior is unchanged.

Evidence

The tool resolves explicit and current plan paths, preserves an open request in tool metadata, and the webview deduplicates repeated event delivery. Focused backend and webview tests, CLI typecheck, extension compile, lint, and Knip passed.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• packages/kilo-vscode/webview-ui/src/App.tsx

Previous Review Summary (commit 43209ae)

Current summary above is authoritative. Previous snapshots are kept for context only.

Previous review (commit 43209ae)

Status: 1 Issue Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	0
SUGGESTION	1

Issue Details (click to expand)

SUGGESTION

File	Line	Issue
packages/kilo-vscode/webview-ui/src/App.tsx	140	Nested DataBridge instances each keep their own opened Set, so Agent Manager can open the same plan twice

Files Reviewed (11 files)

• .changeset/open-plan.md - 0 issues
• packages/kilo-vscode/tests/unit/open-plan.test.ts - 0 issues
• packages/kilo-vscode/webview-ui/src/App.tsx - 1 issue
• packages/kilo-vscode/webview-ui/src/utils/open-plan.ts - 0 issues
• packages/opencode/src/kilocode/agent/index.ts - 0 issues
• packages/opencode/src/kilocode/session/prompt.ts - 0 issues
• packages/opencode/src/kilocode/tool/open-plan.ts - 0 issues
• packages/opencode/src/kilocode/tool/registry.ts - 0 issues
• packages/opencode/test/kilocode/agent-permission-overrides.test.ts - 0 issues
• packages/opencode/test/kilocode/chart-tool-gating.test.ts - 0 issues
• packages/opencode/test/kilocode/tool/open-plan.test.ts - 0 issues

Fix these issues in Kilo Cloud

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_{Reviewed by grok-4.6 · Input: 38.8K · Output: 4.3K · Cached: 239.5K}

_{Review guidance: REVIEW.md from base branch main}