[arudaev]

What and why

The Hidden Garden chunk now has collision in the docs/13 schema.

• Floor: the path at y 441 from the left edge to the end of the jetty.
• Walls: at the left edge, and in the reeds past the jetty, so the walk ends where Dexter points.
• The pond is no-go. Falling in is the scripted crossing, not a reset.
• Spawns: the player on the left; Dexter on the bench.
• Triggers: Dexter's three waypoints (the bench, mid-path where he hops ahead and beckons, the jetty), the pond-edge anomaly trigger for the point and the shove ([M3-S3] Follow Dexter through the Hidden Garden to the pond #50, [M3-S4] The crossing: damage sprite, THD.exe window, landing #51), and a chunk-exit to Rusty Creek.

The ground is flat apart from the jetty. That's what the approved concept draws, and A14 asked for less parkour in the prologue.

Issue

Closes #85

Stack and checker

Stacked on #105 (the chunk), which sits on #104. The checker, collision_check.py, is in #97, so CI here can't run it yet. I ran #97's version locally: 1 file, 0 problems (spawns, triggers and the exit reachable with the 28×76 body). Once #97 and this stack are on main, the art CI checks both regions.

• [4/4] feat: export stage regions with the docs/13 manifest #110 [4/4] feat: export stage regions with the docs/13 manifest
• [3/4] feat: add the Hidden Garden collision and Dexter's waypoints ← this PR
• [2/4] art: draw the Hidden Garden prologue chunk and its layers #105 [2/4] art: draw the Hidden Garden prologue chunk and its layers
• [1/4] feat: split composed stage chunks into the layer stack #104 [1/4] feat: split composed stage chunks into the layer stack

Merge bottom up with merge commits; retarget the next PR to main before merging it.

Screenshots

Legend from docs/04: green floor, red solid, purple trigger, white spawn. The white box is the 28×76 body.