fix(camping): tent clearance + real hammock lie-in behavior

Three fixes for feedback from live testing:

1) Tent pitch check required 3 blocks of air above the footprint but
   the tent is only 2 blocks tall. Relaxed clearance to match the
   actual structure height (h <= 1).

2) Hammock block had a 4px-tall collision box which pushed the player
   on TOP of the cloth. Reduced collision to 1px so the player stands
   inside the hammock cell. Selection box stays at 4px for easy click.

3) Climbing in now actually locks the player: applies slowness 255,
   weakness, mining_fatigue for the duration, saves the anchor point
   in a dynamic property, and the upkeep loop re-teleports them if
   they drift off. Sneak-exit nudges them ~1.2 blocks forward of the
   cradle so they don't immediately re-enter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

camping-supplies-addon/camping_supplies_BP/blocks/hammock_cloth.json

@@ -20,7 +20,7 @@
       },
       "minecraft:collision_box": {
         "origin": [-8, 0, -8],
-        "size": [16, 4, 16]
+        "size": [16, 1, 16]
       },
       "minecraft:selection_box": {
         "origin": [-8, 0, -8],