Marking a location discovered before the move silenced first-visit effects on sixteen locations

One set had two jobs. `discoveredLocationIds` answered "does the player know this place exists", which is what the hidden-passage log line needs ^[2]. It also answered "is this the player's first arrival here", which is what the reward block needs ^[3]. Same storage, different questions, and `travel()` wrote the answer to the first one before performing the move that would have produced the second ^[4]. Retreating from a step the player could not complete did it too: the destination got marked, and the arrival that eventually happened did not count ^[5].

Nothing in the suite was positioned to see this. Connectivity from spawn, every recipe ingredient existing as an item, a victory path per scenario, no dangling ids ^[9]. Each of those is a question about the content files, and the content files were fine: the victory location existed, was reachable, and carried a victory effect ^[10]. A validator that only resolves ids will bless a finish line the player starves in front of ^[7].

The walker is the interesting part, and specifically what it refuses to measure. Every step, the harness refills hydration, body heat, stamina and calories, and clears injury and infection, while leaving the content-side constraints alone: location tags, `disabledActionIds`, per-location exhaustion, flag gates, recipe materials ^[12]. So the current 8/8 ^[15] is a claim about materials and reachability for a player who cannot die of exposure. Transfer it to difficulty balance and it says nothing. The bot also pathfinds ignoring flag gates and, when `travel` refuses, tries the actions that can set the flag it lacks, indexed once from `successEffects` ^[13]. The win condition is read out of content rather than a table, so a redesigned scenario fails instead of quietly passing ^[14].

The instrument-contamination point has a number attached. The author gave the bot one rule, do not travel below 62 body heat, and `frost_ridge` went from 7 wins in 8 runs to 0 ^[18]. On a five-star snow map body heat is rarely above 62, so the bot sat by the fire and froze, with no content change involved ^[19]. Seven of eight is 87.5 percent, zero is zero, and the roughly 88 point swing is that subtraction ^[20]. The harness policy is a variable in the result, which is the argument for keeping the reachability instrument dumber than a human player.

The pass I would defend on the same grounds asserts nothing at all. Given `disabledActionIds` and the tags actually present, it computes a theoretical ceiling on every material a raft or a signal fire needs, direct gathering plus anything craftable, and a ceiling of zero means unwinnable ^[16]. That check exists because these scenarios are designed by subtraction: `highland_mine` disables eight gathering actions, `burnt_range` disables cutting firewood, and deleting a victory material is one edit away from deleting the interesting constraint ^[17]. The fix for the original bug is smaller than any of this. Let `arrive()` own discovery, and log the secret passage after arrival is confirmed ^[8].