v1.6.3-unreleased: Sunstrider zone fixes, QuestieLearner icon preservation, migration, and Busted test suite

Code changes (13 files, +916/-171):
- ZoneDB integration: GetZoneId() converts uiMapId→areaId via ZoneDB reverse lookup
- MIN_CONFIDENCE_PINS reduced to 1 for Ascension (incomplete NPC DBs)
- QuestieLearner icon preservation: objective Icon passed to RegisterObjectiveTooltip
- InjectLearnedData zone migration: converts old uiMapId spawn keys to areaId
- areaId passed through all LearnNPC call sites (OnMouseoverUnit, OnQuestDetail,
  OnQuestComplete, OnQuestAccepted, OnQuestTurnedIn, OnGossipShow)
- Compat/Compat.lua: C_Map.GetPlayerMapPosition UiMapData support
- Compat/HBD.lua: Sunstrider mapData aliases and fallback loading
- Sunstrider arrow fix (QuestieArrow.lua), resolved pin rendering (QuestieMap.lua)
- _MergeOverride helper for string/numeric key compatibility
- Northshire Valley UiMapData registration

Testing infrastructure:
- .busted config pointing to tests/ directory
- Tests/wow_api_mock.lua: WoW API mocks (ZoneDB, C_Map, QuestLogCache, etc.)
- Tests/QuestieLearner_spec.lua: 12 tests covering coordinate scaling, spell cast
  learning, zone migration (NPC/objects), icon preservation, settings defaults,
  and LearnNPC spawn zone tracking
- selene.toml + wow_classic.yml: linter configuration

Documentation:
- Makefile with test/lint/ci targets
- sunstrider-coordinate-collection.md: coordinate data reference
- sunstrider-pin-fix.md: root cause analysis and fix documentation

Compat/UiMapData.lua

@@ -252,6 +252,30 @@ QuestieCompat.UiMapData =
 		["instance"] = 0,
 		["name"] = "Elwynn Forest",
 	},
+	[1238] =
+	{
+		[1] = 968.75,
+		[2] = 645.84,
+		[3] = 187.5,
+		[4] = -8570.83,
+		["mapType"] = 3,
+		["parentMapID"] = 10138,
+		["mapID"] = 1238,
+		["instance"] = 0,
+		["name"] = "Northshire Valley",
+	},
+	[1241] =
+	{
+		[1] = 510,
+		[2] = 500,
+		[3] = -6983.33,
+		[4] = 9766.67,
+		["mapType"] = 3,
+		["parentMapID"] = 1941,
+		["mapID"] = 1241,
+		["instance"] = 0,
+		["name"] = "Sunstrider Isle",
+	},
 	[1430] =
 	{
 		[1] = 2499.9999389648,