enhance(#3913): docs, and the guards come down (#3994)

ADR-3889 terminal phase. Generated docs/reference/exit-codes.md from the exit-code declaration with a --check drift arm; deleted the inert soft-error-exit-zero oracle; promoted untyped-success from SMELL to VIOLATION so it can fail a build; pruned all 5 smell-baseline entries.

Fixed inline: two mis-scoped oracles (routing-validity, value-hygiene), a second source behind the band table, unescaped declaration strings reaching Markdown, and a pre-existing Windows 8.3 short-name path-comparison defect.

Guard ledger corrected from a claimed net -4 to a measured net -1.

Closes #3913

.changeset/lucky-cats-romp.md

@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3994
+---
+**Two QA oracles no longer report findings against the wrong field.** `routing-validity` demanded a live-command token from `recommended`, which is an action id by design, and also validated `recommended_command`, a field nothing in the repo produces; it now checks the fields that actually carry tokens. `value-hygiene` reported command tokens such as `/gsd:progress` as leaked absolute paths, and now exempts them by value shape rather than by key name, so a `command` field holding a genuine absolute path is still reported. (#3913)

.changeset/sturdy-eagles-wave.md

@@ -0,0 +1,5 @@
+---
+type: Added
+pr: 3994
+---
+**A generated exit-code reference at `docs/reference/exit-codes.md`.** Every registered exit code now has a page giving its number, name, meaning and owning band, alongside why `0` and `1` are unallocatable and why `3`-`13` are reserved by Node — so a `69` in a CI log has somewhere to be looked up. The page is generated from the same declaration the registry itself is built from and is `--check`-gated against drift. (#3913)