Fix review findings in the shared wipe tower estimate

A raft is not a reason to reserve a tower. Print::apply runs
normalize_fdm_2, which clears enable_prime_tower for a plate that purges
one filament unless smooth timelapse or wrapping detection is on, so a
single-filament plate with a raft prints no tower at all and the estimate
was reserving bed area for one. Drop the input; need_wipe_tower is now
exactly the two exceptions normalize_fdm_2 honours, named there so the
next reason added has to be checked against it.

The GUI preview and the validation containment check each re-derived
"is a tower printed here" from the filament count instead of reading the
estimate, so both missed the towers printed with no tool change to purge
for. They now take the answer from the footprint, which is the drift this
shared estimate exists to remove. A tower that is not printed estimates to
zero, so its hull is degenerate and every check on it passes trivially -
the containment check needs no gate of its own.

WipeTowerData::width was written only by the pre-generation estimate and
left at zero for the whole post-generation life of the Print, while its
neighbour depth held the real value. Set it from the generator in both
branches.

The plate's height scan transformed every model part's full mesh per
instance on each scene reload, discarding all but the z extent. The
cached convex hull has the same z extent.

A plate loaded from a sliced .gcode.3mf holds no objects and its filaments
live in slice_filaments_info; the config-taking get_extruders overload
returned an empty list for it, which sized the tower for a placeholder two
filaments. It now answers the way the wx overload does, without reaching
the plater.

Also drop estimate_wipe_tower_size, which has no callers.

tests/fff_print/test_wipe_tower.cpp

@@ -199,6 +199,7 @@ static DynamicPrintConfig tower_estimate_config(const char *wall_type)
         { "single_extruder_multi_material", "0"       },
         { "timelapse_type",                 "0"       },
         { "layer_height",                   "0.2"     },
+        { "enable_wrapping_detection",      "0"       },
         { "raft_layers",                    "0"       } });
 }
 
@@ -245,23 +246,83 @@ TEST_CASE("Validation is given the tower's effective width, not the configured o
     }
 }
 
+TEST_CASE("Generating the tower keeps its reported width current", "[WipeTower]")
+{
+    // width is handed out after the slice, so leaving it at the estimate reports a zero-width
+    // tower to every post-generation consumer.
+    const DynamicPrintConfig config = wipe_tower_toolchange_config("marlin");
+    Print print;
+    Model model;
+    init_print({ cube(10) }, print, model, config);
+    print.apply(model, config);
+    REQUIRE(print.wipe_tower_data(2).width > 0.f);
+
+    print.process();
+    REQUIRE(print.is_step_done(psWipeTower));
+    const WipeTowerData &data = print.wipe_tower_data();
+    // A width the generator never wrote reads as zero. A rib wall squares the tower, so the
+    // generated width is the body square: under the configured 50 mm, and inside the depth.
+    CHECK(data.width > 0.f);
+    CHECK(data.width < 50.f);
+    CHECK(data.width <= data.depth + EPSILON);
+}
+
 TEST_CASE("A single-filament plate reserves a tower only when one is actually printed", "[WipeTower]")
 {
-    // Reporting no tower for one that is built collapses the validation hull to a point, so
-    // the config-visible reasons for a single-filament tower have to be honoured.
+    // The estimate has to answer this the way Print::apply does: reporting no tower for one
+    // that is built collapses the validation hull to a point, and reporting one for a tower
+    // that is not built takes that bed area away from the arranger and draws a preview box
+    // over nothing.
     Print print;
     Model model;
 
     SECTION("no tool change and nothing else that prints one") {
         const DynamicPrintConfig config = tower_estimate_config("rib");
         init_print({ cube(20) }, print, model, config);
+        REQUIRE_FALSE(print.has_wipe_tower());
         CHECK_THAT(print.wipe_tower_data(1).depth, Catch::Matchers::WithinAbs(0., 1e-6));
     }
 
-    SECTION("a raft puts the tower on every layer below the object") {
+    // A raft puts the tower on every layer below the object, but only where there is a tower:
+    // Print::apply runs normalize_fdm_2, which clears enable_prime_tower for a plate that
+    // purges one filament and has neither smooth timelapse nor wrapping detection on.
+    SECTION("a raft alone does not print one") {
         DynamicPrintConfig config = tower_estimate_config("rib");
         config.set_deserialize_strict({ { "raft_layers", "3" } });
         init_print({ cube(20) }, print, model, config);
+        REQUIRE_FALSE(print.config().enable_prime_tower.value);
+        REQUIRE_FALSE(print.has_wipe_tower());
+        CHECK_THAT(print.wipe_tower_data(1).depth, Catch::Matchers::WithinAbs(0., 1e-6));
+    }
+
+    SECTION("smooth timelapse prints one, and keeps enable_prime_tower on") {
+        DynamicPrintConfig config = tower_estimate_config("rib");
+        config.set_deserialize_strict({ { "timelapse_type", "1" } });
+        init_print({ cube(20) }, print, model, config);
+        REQUIRE(print.has_wipe_tower());
         CHECK(print.wipe_tower_data(1).depth > 0.f);
     }
 }
+
+TEST_CASE("A tower printed without a tool change is still validated against the bed", "[WipeTower]")
+{
+    // Wrapping detection prints a tower on a plate that purges one filament. Neither the old
+    // estimate (which read the wall type and smooth timelapse) nor the old containment gate (the
+    // filament count or smooth timelapse) knew about it, so between them that tower was never
+    // checked against the bed.
+    Print print;
+    Model model;
+    DynamicPrintConfig config = tower_estimate_config("rectangle");
+    // Relative E without a per-layer G92 is rejected before the tower is ever looked at, and
+    // has_wipe_tower() wants a real exclusion polygon before it honours wrapping detection.
+    config.set_deserialize_strict({ { "enable_wrapping_detection", "1" },
+                                    { "wrapping_exclude_area", "180x180,190x180,190x190,180x190" },
+                                    { "wipe_tower_x", "500" }, { "wipe_tower_y", "500" },
+                                    { "use_relative_e_distances", "0" } });
+
+    init_print({ cube(20) }, print, model, config);
+    REQUIRE(print.extruders(true).size() == 1);
+    REQUIRE(print.has_wipe_tower());
+    CHECK(print.wipe_tower_data(1).depth > 0.f);
+    CHECK_THAT(print.validate().string, Catch::Matchers::ContainsSubstring("printable area"));
+}