fix(minimap): use live Minimap:GetViewRadius() API + corrected pixel math

- Use 3.3.5a-native Minimap:GetViewRadius() (instance method) instead of
  C_Minimap.GetViewRadius (nil on 3.3.5a) with C_Minimap fallback. Returns
  116.67 at zoom 5 instead of the hardcoded 125 from the broken lookup table.
- Replace minimapWidth = (GetWidth()/2) * (mapRadius/155.52) with
  minimapWidth = GetWidth() * GetScale() / 2. The new formula yields the
  actual half-width of the visible minimap in screen pixels, the correct
  multiplier for diffX*minimapWidth when diffX is normalized by mapRadius.
- Comment out (do not delete) all QDMATH / UPDATE entering / ICON debug
  blocks as --[[ DEBUG: ... --]] for future regression investigation.
- Remove loaded debug scripts from Questie-X.toc and add to .gitignore
  (drift_test, radius_debug, spawn_calibration, etc.). Scripts preserved
  in tests/ for reference.
- Add .gitignore entries for tests/ lowercase variant (case-sensitive
  on Linux/macOS) and additional debug script patterns.
- Update CHANGELOG.md and docs/changelog.html with fix entry.
- Refresh handoff.md to reflect RESOLVED status and iteration 4 history.

Verified: pins now stay anchored to world positions across all zoom levels
on both Stock UI and ElvUI. Per-frame diffX ~0.35 yards during walking
translates to ~0.21 pixels of pin movement (correct for 1 yard of world
movement).

.gitignore

@@ -4,6 +4,7 @@ Tools/
 
 # Test files
 Tests/
+tests/
 Modules/*_spec.lua
 
 # Dev notes and session artifacts
@@ -11,6 +12,7 @@ docs/sunstrider-pin-fix.md
 docs/sunstrider-coordinate-collection.md
 docs/PROGRESS.md
 docs/testing-macros.md
+handoff.md
 QUESTIE-LEARNER-HANDOFF.md
 
 # Generated/lock files
@@ -54,3 +56,16 @@ wow_classic.yml
 # Dev scripts
 Makefile
 move_recompile.py
+
+# Minimap drift investigation scripts (legacy — see tests/ for archived copies)
+drift_test.lua
+drift_verification.lua
+spawn_calibration.lua
+debug_coords.lua
+minimap_calibration.lua
+radius_debug.lua
+diagnostic_minimap_drift.lua
+elvui_debug.lua
+elvui_terrain_audit.lua
+Compat/HBD.lua.backup
+Compat/HBD.lua.bak