feat(bot): add tool configuration knowledge to triage bot

[DimaBir]

Summary

• Fixes triage bot permissions: issues: read -> issues: write (bot was failing with "Resource not accessible by personal access token" on safe_outputs)
• Adds tool-specific configuration knowledge to bot prompt (env var pattern, per-tool examples, .gdnconfig format)
• Expands add-labels allowlist with area: labels
• Makes fetch tool usage explicit per gh-aw best practices
• Adds response example for tool config questions

Companion change: Tool-Configuration wiki page (already published)

Test plan

• Re-trigger the triage bot on issue checkov fails to download external modules #235 to confirm labels and comments are posted
• Open a test issue asking about tool configuration and verify the bot responds with env var pattern
• Verify the bot can fetch and reference the new wiki page
• Confirm area: labels can be applied by the bot