Eingraben: 2 s move inside a barrier turning solid, 4 s duration

The barrier's model alpha goes to opaque over 1 s, the dwarf is moved,
and it clears over 1 s; orders to him are refused meanwhile (new
game::FilterCreatureOrders). The art's duration in its definition is a
fixed 4 s (was 7 + level), which the barrier, its bonus and the tooltip use.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/dwarf-arts.md

@@ -120,7 +120,24 @@ Mod (`mods/dwarfarts.cpp`): Eingraben's definition +0x3c becomes 3 (a point);
 after the original case the dwarf is teleported to the end of
 Phasenverschiebung's walk towards the point (the cursor keeps it within the
 visible area). The effect hook (`aurarecast.cpp`, `KeepEffect`) drops kind
-0x3a for art 0x39 and cuts the art's other effects to 3 s. Confirmed
-2026-10-28: aimed, stops before walls and cliffs, casts at once at the screen
-edge, the barrier moves with him, no lock, bonus for 3 s. Open: clearing
-slows and stuns, 1 s digging in and out.
+0x3a for art 0x39. Confirmed 2026-10-28: aimed, stops before walls and
+cliffs, casts at once at the screen edge, the barrier moves with him, no lock.
+
+Duration ("more like 8 seconds as described in the tooltip, i want that to go
+down to 4 seconds"): an art's duration is 0x4d24f0 on its definition,
++0x76 + level x +0x78, at most +0x82 when set (Eingraben: 7 + level, at most
+15). The barrier's lifetime (shield +0x20a8), its bonus (the effect applier,
+0x5b56ab) and the tooltip all use it; the mod sets 4 / 0 / 0.
+
+Digging in and out: lowering the dwarf's height (creature +0xf0) moved only
+his marker; lowering the terrain height the game asks for him (0x449b20)
+moved the camera with him, so he never looked sunk. Instead ("change the
+barrier animation to turn from transparent to solid and back"): the barrier
+is `cParticleSystem_dwarf_shield` (constructor 0x7b8fc0, update vf08
+0x7b91a0, draw vf04 0x7b92b0; models fx_shield_phase1..4.grn). Its draw
+passes the model with alpha pulse x 128 (pulse 0.4..1 at +0x20b8; __ftol at
+0x7b9483), then again additively. The mod redirects that __ftol: during a dig
+the alpha goes to 255 over 1 s, the dwarf is moved (engine tick), and it goes
+back over 1 s. Orders to the dwarf are refused meanwhile
+(`game::FilterCreatureOrders`). Confirmed 2026-10-28, barrier and bonus 4 s.
+Open: clearing slows, roots and stuns.