[Docs]: cascade_runbook.md FD-exhaustion cross-reference uses single hyphen where GitHub slug has double hyphen

[Fearvox]

Area: documentation

Page or file: docs/cascade_runbook.md (line 207)

What should be improved?

The LanceDB index-cache section links [Recovery paths § FD exhaustion](#fd-exhaustion-os-error-24-emfile). The target heading is ### FD exhaustion (\os error 24` / EMFILE)(line 146). GitHub derives its anchor slug by lowercasing, stripping backticks/parentheses/slashes, and converting spaces to hyphens. Because the heading contains / (space-slash-space), removing the slash leaves two adjacent spaces, which become a **double** hyphen:fd-exhaustion-os-error-24--emfile`. The link uses a single hyphen, so it matches no anchor and is dead.

Steps to reproduce

1. Open docs/cascade_runbook.md on GitHub (rendered Markdown).
2. Locate the ### LanceDB index cache section (around line 201) and the FD cross-reference at line 207.
3. Click Recovery paths § FD exhaustion.
4. Observe the page does not scroll to the FD-exhaustion section (line 146).
5. Confirm the real slug: the heading FD exhaustion (\os error 24` / EMFILE)renders the anchor#fd-exhaustion-os-error-24--emfile` (double hyphen).

Expected vs actual

• Expected: #fd-exhaustion-os-error-24--emfile (double hyphen), which scrolls to the FD-exhaustion section.
• Actual: #fd-exhaustion-os-error-24-emfile (single hyphen), a dead anchor.

Environment

• Repo: EverMind-AI/EverOS
• File: docs/cascade_runbook.md
• Commit: 306dcfe (upstream/main as filed)
• Renderer: GitHub Markdown (GitHub-flavored slug algorithm)

Suggested wording or structure

Change the fragment to #fd-exhaustion-os-error-24--emfile (double hyphen between 24 and emfile).

A fix is staged at https://github.com/Fearvox/EverOS/pull/new/proofstorm/r1-doc-dead-xrefs.