Implement runtime variable event conditions

docs/README.md

@@ -114,14 +114,17 @@ The highest-value next passes are now:
   through stable normalized keys such as `world.build_stations_cost` and
   `world.track_maintenance_cost`
 - the runtime-variable strip `39..54` now executes too through bounded event-owned scalar maps on
-  world/company/player/territory state; these variables are runtime-owned only in the current
-  model and are not yet reconstructed from raw saves
+  world/company/player/territory state, and the matching ordinary-condition strip now gates
+  imported records through those same runtime-owned variable maps; these variables are still
+  runtime-owned only in the current model and are not yet reconstructed from raw saves
 - the grounded aggregate cargo-economics descriptors now execute too: descriptor `105`
   `All Cargo Prices` and descriptors `177..179` `All Cargo Production` / `All Factory Production`
   / `All Farm/Mine Production` land on bounded event-owned cargo override state, and the grounded
   named cargo-production strip `180..229` now lands on named cargo production overrides too
 - the named cargo-price strip `106..176` remains explicit
   `blocked_evidence_blocked_descriptor` parity until descriptor ordering is pinned more strongly
+- the add-building strip `503..519` is now explicitly classified as recovered shell-owned parity,
+  with tracked fixture coverage, instead of generic unresolved descriptor residue
 - widen real packed-event executable coverage descriptor by descriptor after identity, target mask,
   and normalized effect semantics are all grounded, not just after row framing is parsed
 - the first grounded condition-side unlock now exists for negative-sentinel `raw_condition_id = -1`