feat: add issue triage skill

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

.claude/skills/triage-issues/SKILL.md

@@ -0,0 +1,135 @@
+---
+name: triage-issues
+description: >
+  Triage one or more GitHub issues for the docker/docs repository. Analyzes each
+  issue's content, checks whether the problem still exists in the repo and on the
+  live site, and produces a structured verdict. Use this skill whenever the user
+  asks to triage, analyze, review, or assess GitHub issues — e.g. "triage issue
+  1234", "what's the status of these issues", "which of these can be closed",
+  "look at issues 100 200 300 and tell me what to do with them".
+---
+
+# Triage Issues
+
+Given one or more GitHub issue numbers from the docker/docs repository, analyze
+each issue and produce a structured verdict on its current status.
+
+## Workflow
+
+### 1. Fetch all issues in parallel
+
+For each issue number, fetch everything in a single call:
+
+```bash
+gh issue view <number> --repo docker/docs \
+  --json number,title,body,state,labels,createdAt,updatedAt,closedAt,assignees,author,comments
+```
+
+When triaging multiple issues, fetch all of them in parallel before starting
+analysis — don't process one at a time.
+
+### 2. Analyze each issue
+
+For each issue, work through these checks:
+
+#### a. Understand the problem
+
+Read the issue body and all comments. Identify:
+- What is the reported problem?
+- What content, URL, or file does it reference?
+- Are there linked PRs? Check whether they were merged or closed without merge.
+- Has anyone already proposed a fix or workaround in the comments?
+
+#### b. Follow URLs
+
+Find all `docs.docker.com` URLs in the issue body and comments. For each one:
+- Fetch the URL to check if it still exists (404 = content removed or moved)
+- Check whether the content still contains the problem described
+- Note when the page was last updated relative to when the issue was filed
+
+For non-docs URLs (GitHub links, external references), fetch them too if they
+are central to understanding the issue.
+
+#### c. Check the repository
+
+If the issue references specific files, content sections, or code:
+- Use file tools to find and read the current version of that content
+- Check whether the problem has been fixed, the content moved, or the file removed
+- Remember the `/manuals` prefix mapping when looking up files
+
+#### d. Check for upstream ownership
+
+If the issue is about content in `_vendor/` or `data/cli/`, it cannot be fixed
+here. Identify which upstream repo owns it and note that in your analysis.
+
+### 3. Determine verdict
+
+Assign one of these verdicts based on what you found:
+
+| Verdict | When to use |
+|---------|-------------|
+| **OPEN** | Issue is valid and still unfixed in this repo |
+| **CLOSEABLE_FIXED** | Content has been updated, corrected, or removed since the issue was filed |
+| **UPSTREAM** | Problem exists but originates in vendored/upstream content |
+| **INDETERMINATE** | Not enough information to determine current state |
+| **STALE** | Outdated with no recent activity; references content or features that no longer exist; context has changed enough that a new issue would be more appropriate |
+
+Be confident when evidence is clear. Use INDETERMINATE only when you genuinely
+cannot determine the current state after checking.
+
+### 4. Report results
+
+#### Single issue
+
+Print a structured report:
+
+```
+## Issue #<number>: <title>
+
+**Verdict:** <VERDICT>
+**Confidence:** <high|medium|low>
+**Filed:** <creation date>
+**Last activity:** <last comment or update date>
+**Labels:** <labels or "none">
+
+### Summary
+<One or two sentences describing the reported problem.>
+
+### Analysis
+<What you checked and what you found. Reference specific URLs, files, or
+content. Note any linked PRs or related issues.>
+
+### Recommendation
+<Concrete next step: close with a comment, fix specific content, escalate
+to upstream repo, request more info from reporter, etc.>
+```
+
+#### Multiple issues
+
+Start with a summary table, then print the full report for each issue:
+
+```
+| Issue | Title | Verdict | Confidence |
+|-------|-------|---------|------------|
+| #123  | ...   | OPEN    | high       |
+| #456  | ...   | STALE   | medium     |
+
+---
+
+## Issue #123: ...
+[full report]
+
+---
+
+## Issue #456: ...
+[full report]
+```
+
+## Notes
+
+- A merged PR linked to an issue is strong evidence the issue is fixed
+- A closed-without-merge PR means the issue is likely still open
+- Check creation date and last activity to assess staleness — issues with no
+  activity in over a year that reference old product versions are candidates
+  for STALE
+- Do not narrate your process; just produce the final report(s)