Merge origin/main (v1.91.9.0, #2998) into capy/audit-fix-wave; release as v1.91.10.0

Main shipped v1.91.9.0, so this wave becomes v1.91.10.0. Conflicts kept this
branch's planner-derived assertions. Main's new test-value eval gets rule
kinds for its three gate cases and its measured 332 s duration from #2998's
CI; census counts and the PR fallback floor follow the new file. The packing
test now weighs each tier's recorded durations the way the planner does.

agents-digest/gstack-AGENTS.md

@@ -1,4 +1,4 @@
-# gstack digest v1.91.9.0 — regenerate/re-copy after upgrading gstack
+# gstack digest v1.91.10.0 — regenerate/re-copy after upgrading gstack
 
 Behavioral rules from gstack (https://github.com/garrytan/gstack), compressed
 for agent hosts without a full skill install. The full skills add workflows,