[neeerp]

LEDGER row 198 (lane A). Research: v83ref reports a049 (facts/design) and a050 (client display of 0x7A/0x31); review a051-a053.

• Counting: entering a region's explorationPoint map, from the medal's lvmin, counts it once toward that region's explorer title (29005-29011, 29014; net::medals::region follows the map-id ranges). The highposition touch portals count toward Touched the Sky (29004) and take the player nowhere.
• Messages: the first place starts the quest. Each new place sends the info record with the count, a SCRIPT_PROGRESS_MESSAGE (0x7A) line and an info text. The place that reaches the count sends QUEST_CLEAR (0x31), the title line and the "see Dalair" note.
• The medal: Dalair (9000040) gives it through QUEST_ACTION once the count is reached (QuestRejection::Explored). The explorer quests are now supported.
• Storage: places live in the new explored_maps table, keyed by info record. They outlast a forfeit, and a forfeited medal starts again on its next region map. At login a started medal's record is sent among the started quests with its count.
• Texts: new keys medal.explorer.*, as placeholders.
• Not in this PR: HeavenClient doesn't handle 0x7A or 0x31 yet; a follow-up client slice will add them.
• Defaults with no source: the level gate, leaving out 29012/29013 and keeping places across a forfeit are listed in lanes/QUESTIONS.md, with the recommended defaults shipped.

Tests

• Unit tests in medals, scripts, quests and game::quest.
• New harness test medal_explorer: level gate, count, repeat, forfeit and restart, login count, the last map's packets, Dalair's medal, no counting after completion, and highposition.
• Full harness suite: 180 passed, 0 failed, run on the first commit. After the review fixes and the rebase, the targeted tests (medal_explorer, families, quest_alert, rain_quizzes) and the net/game/game-data unit tests pass.