Move triage instructions to a gemini skill (#8736)

This is from following https://geminicli.com/docs/cli/skills/

It seems better for organization to have this all in the .gemini folder.

<img width="1113" height="445" alt="Screenshot 2026-01-28 at 9 10 26 AM" src="https://github.com/user-attachments/assets/c25fa528-8878-4aff-9a81-105383a3f43d" />

Author: helin24

.gemini/skills/triage/SKILL.md

@@ -0,0 +1,22 @@
+---
+name: triage-helper
+description: Assistance with triage of unprioritized issues. Use when the user asks for help with triage.
+---
+
+When a user asks for help in the CLI:
+- Find the latest open issues in the https://github.com/flutter/flutter-intellij/ repo that don't have a priority label.
+- If you encounter authentication issues, guide the user to check their `github-mcp-server` setup or `gh auth status` depending on available tools.
+- Reference `docs/Triaging.md` for detailed setup instructions.
+- Consider the most recently updated issues first. Start presenting issues one at a time to the user, with the issue URL and other relevant information.
+- For each issue, give suggestions such as:
+    - Close the issue if it's not relevant anymore (e.g. it's been fixed, the code it's referencing is outdated, etc.)
+    - Suggest how to reproduce if it looks like it may be easy to reproduce locally
+    - Ask for a reproduction with a small project if reproduction may be hard locally
+    - Ask for more information and apply a waiting for response label
+    - Note a code pointer for the issue if it could be a good first issue for an external contributor
+    - Suggest a priority and other labels that may be relevant along with reasoning for the priority
+- Then wait for user feedback before continuing on to the next issue.
+
+Avoid executing tasks on GitHub directly, such as making comments, applying labels, or closing issues.
+
+There is additional context on our issue triage process in docs/Triaging.md.

docs/Triaging.md

@@ -68,7 +68,7 @@ Once in the gemini CLI, you can say something like "help me with triage". Exampl
 ```
 
 Notes:
-- There are instructions for gemini in the `tool/triage/GEMINI.md` file, and gemini should be able to access this whenever you start
+- There is a triage skill for gemini in the `.gemini/skills` directory, and gemini should be able to access this whenever you start
 `gemini` in the flutter-intellij directory.
 - This extension can also help with reviewing PRs, or any other tasks that require context from GitHub.