The rung-11 reading of row 54. Route 3's connections read north and west off the cartridge
(`wCurMapConnections`, and it has no warps at all) while the geography table carries west and east,
so the seven walkable tiles of its north edge had an unnameable destination -- and an unnameable
destination counted as unvisited, which made them first-tier for `GO ROUTE` on every hold for ever,
with `GO OBJECTIVE` off the pad beside them because nothing on that map leads to the objective.
A warp's destination is a byte the cartridge publishes, so `None` there is the `LAST_MAP` case
already handled. An edge's comes only from `geography::connected`, so `None` there means the table
cannot name the map on the other side and never will, and the only record left is the adapter's own
boundary ledger. It narrows: a genuinely new edge is still first-tier until the fly reaches it.
Which map is north of Route 3 is not guessed at here. That is a survey -- walk the fly off the edge
with real presses and read the map id back -- and it is recorded as a residual instead.
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