fix(github-issues): ban conventional commit prefixes in issue titles

Issue titles were being created with fix(x):, feat(x):, ref(x): etc.
These formats belong in commit messages and PR titles, not GitHub issues.

Added explicit hard constraint in SKILL.md and anti-pattern in
issue-examples.md to prevent this.

Co-Authored-By: sentry-junior[bot] <264270552+sentry-junior[bot]@users.noreply.github.com>

Author: dcramer

packages/junior-github/skills/github-issues/SKILL.md

@@ -52,6 +52,7 @@ Follow [references/research-rules.md](references/research-rules.md) for cross-ty
 **Hard constraints — apply to every new issue:**
 
 - Title ≤ 60 characters. Descriptive for bugs, imperative for tasks/features.
+- **No conventional commit prefixes in issue titles.** Do not prefix with `fix(x):`, `feat(x):`, `chore:`, `ref(x):`, or similar. Those formats belong in commit messages and PR titles — not GitHub issues.
 - Summary ≤ 3 sentences. Do not restate the title in the body.
 - Prefer flat bullet lists over headed sections for simple issues. Remove empty sections.
 - Generalize session framing — strip channel references, slash commands, Slack thread IDs, user @mentions, and transcript fragments; replace with the underlying technical problem.

packages/junior-github/skills/github-issues/references/issue-examples.md

@@ -99,6 +99,7 @@ Good framing — current state, gap, options:
 
 ## Anti-patterns
 
+- Conventional commit prefixes in issue titles: `fix(scope): ...`, `feat(x): ...`, `chore: ...`, `ref(x): ...` — those belong in commits and PR titles, not issues
 - Over-structured issues: using ## Summary, ## Impact, ## Root Cause headings for a 3-line bug
 - Adding "Expected behavior" or "Desired outcome" when the thread didn't state one
 - Restating the title as the first sentence of the body