Add bootstrap script support for tasks

[Copilot]

Extends bootstrap script functionality from rules to tasks. Bootstrap scripts (executable files with -bootstrap suffix) prepare the environment before processing, enabling dynamic data fetching, dependency installation, and environment setup.

Changes

• main.go: Call runBootstrapScript() for task files before content emission (5 lines)
• integration_test.go: Add 3 tests covering task bootstrap execution, optional bootstrap, and rule+task bootstrap interaction
• README.md: Document task bootstrap in "How It Works" and "Bootstrap Scripts" sections

Naming & Execution

.agents/tasks/fix-bug.md       → .agents/tasks/fix-bug-bootstrap
.agents/rules/jira.md          → .agents/rules/jira-bootstrap

Execution order: rule bootstraps → rules → task bootstrap → task content

Example

#!/bin/bash
# .agents/tasks/fix-bug-bootstrap
echo "Fetching issue ${issue_number} details..." >&2
gh issue view ${issue_number} --json title,body > /tmp/issue.json

Bootstrap output goes to stderr. Scripts are optional and auto-chmod'd to executable.

Original prompt

Add support for bootstraping to tasks as well as rules.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[swedishborgie]

LGTM!