fix: H2C carousel - port BBS NozzleStatusRecorder for per-slot purge tracking (#14800)

## Problem

On H2C (carousel) printers, the wipe tower purge volume calculation in
`_make_wipe_tower()` tracks filament state **per-extruder** (2 slots).
Since H2C has up to 7 carousel nozzle slots on a single extruder, all
filaments sharing that extruder are collapsed into one tracking slot.
This causes:

Test:

[5cubes.3mf.zip](https://github.com/user-attachments/files/30092551/5cubes.3mf.zip)

- **Massive redundant AMS flushing** every filament change on the
carousel triggers a full purge against the "previous" filament, even
when the target nozzle slot already has the correct filament loaded
- **60.9g total weight** instead of ~17g (**3.5× material waste**)
- **3h09m print time** instead of ~1h57m (**60% longer**)

## Root Cause

The code uses `nozzle_cur_filament_ids[extruder_id]` (a 2-element array)
to track which filament was last used for each extruder. BambuStudio
uses `NozzleStatusRecorder`, which tracks per `group_id` (physical
carousel slot 0..6).

## Changes

| File | Change |
|---|---|
| `Print.cpp` | Replace `nozzle_cur_filament_ids` with
`NozzleStatusRecorder`. Use `get_nozzle_for_filament()` to resolve the
physical carousel slot per layer. Select `filament_prime_volume_nc` for
nozzle changes, `filament_prime_volume` for filament changes. |
| `PrintConfig.hpp` | Add `ConfigOptionFloats filament_prime_volume`
(per-filament EC prime volume, missing from upstream but present in BBS
and H2C profiles) |
| `PrintConfig.cpp` | Register `filament_prime_volume` with default
45mm³ (matching BBS) |
| `Preset.cpp` | Add `filament_prime_volume` to preset keys |

Also includes `tests/compare_analyzer/` - two standalone Python tools
for G-code slice comparison and temperature timeline analysis (stdlib
only, no dependencies).

## Test Results (5-color H2C Hybrid print, same 3mf project)

| Metric | Upstream (broken) | **Fixed** | BBS (reference) |
|---|---|---|---|
| **Total weight** | 60.90g | **16.20g** ✅ | 17.47g |
| **Print time** | 3h09m | **1h57m** ✅ | 1h51m |
| **Filament changes** | 105 | 105 | 140 |
| **Tool changes** | 35 | 35 | 35 |
| **Critical discrepancies vs BBS** | ⚠️ YES | ✅ None | — |


## Analysis Tools (`tests/compare_analyzer/`)

Two standalone Python tools (stdlib only, no dependencies) for deep
G-code comparison:

- **`compare_slices.py`** - comprehensive .3mf slice comparison:
filament usage, nozzle mapping, tool change sequences, prime tower
analysis, temperature timeline, retract parameters, and automatic
critical discrepancy detection (weight/time anomalies)
- **`show_temp_plot.py`** - interactive HTML temperature timeline
plotter for visualising heater profiles during multi-nozzle prints
(supports single-file and side-by-side comparison)

Usage:
```bash
python3 tests/compare_analyzer/compare_slices.py file1.3mf file2.3mf --labels "Upstream" "Fixed"
python3 tests/compare_analyzer/show_temp_plot.py file1.3mf file2.3mf
```


## Screenshots

### OrcaSlicer Upstream (unfixed) - 60.90g, 3h09m
<img width="1512" height="982" alt="Screenshot 2026-07-16 at 15 22 58"
src="https://github.com/user-attachments/assets/3efb2bff-ff1e-43db-9669-feafa5921b51"
/>


### OrcaSlicer Fixed - 16.20g, 1h57m
<img width="1512" height="982" alt="Screenshot 2026-07-16 at 15 23 08"
src="https://github.com/user-attachments/assets/c1d36dc5-9b01-4691-80ef-7364540e1f4e"
/>

### BambuStudio Reference - 17.47g, 1h51m
<img width="1512" height="982" alt="Screenshot 2026-07-16 at 15 24 52"
src="https://github.com/user-attachments/assets/5c0b11e2-64f4-40e9-8c7c-3f42519786c3"
/>

### Temperature Timeline: Upstream vs Fixed
<img width="1511" height="829" alt="Screenshot 2026-07-16 at 15 23 35"
src="https://github.com/user-attachments/assets/926c2cb5-dfd4-4ce0-bb40-82e6165eb134"
/>


### Temperature Timeline: Fixed vs BBS

<img width="1512" height="825" alt="Screenshot 2026-07-16 at 15 23 51"
src="https://github.com/user-attachments/assets/85c72dda-e779-4aa6-8118-fb17e5f8482d"
/>


## Compatibility

Safe for non-carousel printers: when each extruder has a single nozzle,
`group_id == extruder_id`, so `NozzleStatusRecorder` behaves identically
to the original per-extruder tracking. The `filament_prime_volume`
default (45mm³) matches the existing global `prime_volume` default.

## Reference
BambuStudio `Print.cpp` `_make_wipe_tower()` L3341-3392 -
`NozzleStatusRecorder` pattern.

src/libslic3r/PrintConfig.cpp

@@ -7384,7 +7384,7 @@ void PrintConfigDef::init_fff_params()
     def->tooltip = L("The flush multiplier used in fast purge mode.");
     def->set_default_value(new ConfigOptionFloats{1.2});
 
-    // BBS
+    // Orca: used by the generic (Type2) wipe tower; also the fallback for filament_prime_volume on Type1.
     def = this->add("prime_volume", coFloat);
     def->label = L("Prime volume");
     def->tooltip = L("This is the volume of material to prime the extruder with on the tower.");
@@ -8030,6 +8030,16 @@ void PrintConfigDef::init_fff_params()
     def->mode = comDevelop;
     def->set_default_value(new ConfigOptionBool(false));
 
+    // Used by the Type1 wipe tower: filament_prime_volume on a filament change,
+    // filament_prime_volume_nc on a hotend/nozzle change. Type2 uses prime_volume instead.
+    def           = this->add("filament_prime_volume", coFloats);
+    def->label    = L("Filament change");
+    def->tooltip  = L("The volume of material required to prime the extruder on the tower, excluding a hotend change.");
+    def->sidetext = L("mm³");
+    def->min      = 1.0;
+    def->mode     = comSimple;
+    def->set_default_value(new ConfigOptionFloats{45.});
+
     def           = this->add("filament_prime_volume_nc", coFloats);
     def->label    = L("Hotend change");
     def->tooltip  = L("The volume of material required to prime the extruder for a hotend change on the tower.");
@@ -9050,7 +9060,7 @@ void PrintConfigDef::handle_legacy(t_config_option_key &opt_key, std::string &va
         "retraction_distance_when_cut",
         "internal_bridge_support_thickness", "top_area_threshold", "reduce_wall_solid_infill","filament_load_time","filament_unload_time",
         "smooth_coefficient", "overhang_totally_speed", "silent_mode",
-        "overhang_speed_classic", "filament_prime_volume",
+        "overhang_speed_classic",
         "anisotropic_surfaces", // superseded by top_surface_fill_order / bottom_surface_fill_order
     };