Fix stale-issues naming/link drift in setup docs

[Copilot]

This PR fixes stale-issues naming drift in setup documentation so workflow IDs and links match the current split implementation.

What changed

• Updated README.md recommended continuous-improvement workflow list to replace legacy stale-issues with:
  • stale-issues-investigator
  • stale-issues-remediator
• Updated gh-agent-workflows/README.md workflow catalog to replace the broken stale-issues/ link with:
  • stale-issues-investigator/
  • stale-issues-remediator/
• Updated gh-agent-workflows/README.md --continuous-improvement install list to use the same two workflow IDs used by scripts/quick-setup.sh.

Why

The docs previously referenced a deprecated single workflow name and a non-existent directory link, which could mislead users during setup.

Related: #492

Generated by Update PR Body for issue #496

[strawgate]

/ai let's shorten this and just include it as a bullet point going from 0.2.whatever to Latest and then when we do a release we can always update it. We dont need to describe everything like its a changelog, just breaking stuff. Let's also list out the other workflow copies in the repo that only exist for backwards compatibility and tell downstream users to rename to the new ones.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 0e7f2a2 and 232f93f.

📒 Files selected for processing (1)

• docs/upgrading.md

---

📝 Walkthrough

Walkthrough

This PR updates documentation to reflect a split of the continuous-improvement "stale-issues" workflow into two specialized workflows: stale-issues-investigator and stale-issues-remediator. Changes update the main README "Top recommended workflows", the gh-agent-workflows README (detectors list and quick-setup references), and docs/upgrading.md (renamed heading, removal of historical migration sections, and addition of explicit backwards-compatibility file rename examples).

Possibly related PRs

• PR 474 — README edits that mirror the stale-issues split into stale-issues-investigator and stale-issues-remediator.
• PR 490 — Workflow-level rename/split that replaces stale-issues with the investigator and remediator workflows.
• PR 341 — Adds scripts/workflow copies for backwards-compatibility renames referenced in the upgraded docs.

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The PR comprehensively addresses all three objectives from issue #492: updated README.md to replace stale-issues with both investigator and remediator workflows, fixed broken link in gh-agent-workflows/README.md, and aligned --continuous-improvement list with quick-setup.sh behavior.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing stale-issues documentation drift across README.md and gh-agent-workflows/README.md, with no extraneous modifications.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch copilot/fix-stale-issues-naming

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[cla-checker-service]

❌ Author of the following commits did not sign a Contributor Agreement:
, , c543237,

Please, read and sign the above mentioned agreement if you want to contribute to this project