fix(model-router): close the accepted residuals of waves 1-4

Kill switch fails closed: a present-but-unreadable override at first load
or a non-boolean enabled turns the router off (logged); /route reload says
when the previous config was kept. Prompt rules with nested quantifiers
are dropped; a config path that is not a regular file reads as failed;
caught errors log kind + code only (errWord); rejected keys are masked in
logs (keyWord), alias keys match KEY_NAME, prototype names are never keys;
offers capped at 256; a models alias without a fallback list is ranked at
the end of the default chain; canonical matches a table id at a '-'
boundary only; logCall/noteMain cannot unroute a step; route-tool failure
text no longer claims nothing was routed.

Repo side: mods suite probes the 'claude plugin test' usage line, doctor
bounds plugin list to 60 s, update-all skips @skills-dir mods.
Kit 431/431, full make test green.

update-all.sh

@@ -599,6 +599,9 @@ if command -v claude &>/dev/null; then
   if [ -n "$_plugins" ]; then
     while IFS= read -r _p; do
       _name="${_p%%@*}"
+      # A mod loaded from skills/ (@skills-dir) lives in this repo: nothing
+      # to fetch, and `plugin update` warns on it every run.
+      case "$_p" in *@skills-dir) info "$_name: in-repo mod, skipped"; continue ;; esac
       info "Updating $_name..."
       # Pass the full "name@marketplace" spec — the CLI rejects
       # the bare name when several marketplaces are registered.