Shot Viewer: build shot cameras with Add Camera Rigs

New shot cameras come from bpy.ops.object.build_camera_rig: a crane rig
when "3D Camera" is ticked, a 2D rig otherwise (SHOT_CAMERA_RIG_MODES).
The camera and its rig are named for the sequence and shot
(SHOT_CAMERA_RIG_NAME_FORMAT). Camera rigs are left out of the rig
quick-select. Requires the Add Camera Rigs extension.

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

README.md

@@ -29,6 +29,8 @@ Most values the tools rely on (prefixes, shot naming, frame rate…) live in `co
 
 Tested on **Blender 5.2**.
 
+The Shot Viewer builds its cameras with the **Add Camera Rigs** extension (*Edit > Preferences > Get Extensions*, search "Add Camera Rigs"). Install and enable it next to Melvile Tools.
+
 **As an extension (artists):** build the package, then in Blender go to *Edit > Preferences > Get Extensions > Install from Disk…* and pick the `.zip`.
 
 ```bash
@@ -279,11 +281,12 @@ Click **+** next to the shot list:
 |---|---|
 | **Name** | Pre-filled with the next free shot number (`sh0010`, `sh0020`…). This is the marker name. |
 | **Duration** | Length of the shot in frames. |
-| **New Camera** | On: creates the camera `CAM_<sequence>_<shot>` (its name is shown in the dialog), copying the lens and position of the current camera, so you start from the current framing. Off: pick an existing camera of the scene. |
+| **New Camera** | On: builds a camera rig with the **Add Camera Rigs** add-on. The camera is named `CAM_<sequence>_<shot>` (shown in the dialog) and its rig `RIG_<sequence>_<shot>`. Off: pick an existing camera of the scene. |
+| **3D Camera** | On: a 3D **crane** rig. Off: a **2D** camera rig. |
 
 The shot is added at the end of the sequence and the scene's **End** frame grows to include it. The first shot starts at frame 1001, and the scene **Start** moves there too. The playhead and the 3D view then jump to the new shot.
 
-New cameras go in the scene's top collection: move them into your camera collection if you have one.
+The rig is built at the **3D cursor**, in the active collection: place the cursor and pick the collection first if you have a camera collection. The add-on keeps the rig's bone shapes in a hidden **Widgets** collection. If the add-on is not enabled, the dialog says so and no shot is added.
 
 ### Deleting a shot
 
@@ -304,7 +307,7 @@ The bottom of the panel lists the armatures of the scene, grouped into **Charact
 - **Shift+click**: adds it to the selection, to pose several rigs at once.
 - The rig(s) currently selected are highlighted.
 
-A rig counts as a character or a prop when its name, one of its collections, or the library file it comes from starts with `chr_` / `prp_` (see `SHOT_VIEWER_RIG_GROUPS` in [Configuration](#configuration)). Hidden rigs cannot be selected.
+A rig counts as a character or a prop when its name, one of its collections, or the library file it comes from starts with `chr_` / `prp_` (see `SHOT_VIEWER_RIG_GROUPS` in [Configuration](#configuration)). Hidden rigs cannot be selected. Camera rigs (armatures carrying a camera) are not listed.
 
 ---
 
@@ -329,7 +332,7 @@ To change them **without editing the code**, write a JSON file with the keys to
 
 Unknown keys are ignored and reported in the system console.
 
-Name formats use Python's `str.format`: `"sq{:04d}"` turns `10` into `sq0010`. `SHOT_CAMERA_NAME_FORMAT` takes the named tokens `{prefix}` (the camera prefix of `OBJECT_PREFIXES`, `CAM_`), `{sequence}` and `{shot}`. The default `"{prefix}{sequence}_{shot}"` gives `CAM_sq0010_sh0030`.
+Name formats use Python's `str.format`: `"sq{:04d}"` turns `10` into `sq0010`. `SHOT_CAMERA_NAME_FORMAT` takes the named tokens `{prefix}` (the camera prefix of `OBJECT_PREFIXES`, `CAM_`), `{sequence}` and `{shot}`. The default `"{prefix}{sequence}_{shot}"` gives `CAM_sq0010_sh0030`. `SHOT_CAMERA_RIG_NAME_FORMAT` names the rig the same way, with `{prefix}` = `RIG_`. `SHOT_CAMERA_RIG_MODES` picks the Add Camera Rigs mode for 3D and 2D cameras (`CRANE` and `2D`; `DOLLY` is also available).
 
 ### Keys by tool
 
@@ -343,7 +346,7 @@ Name formats use Python's `str.format`: `"sq{:04d}"` turns `10` into `sq0010`. `
 | Sanity Check: layout | `SET_COLLECTION_PATTERN` |
 | Sanity Check: panel | `CATEGORY_ORDER`, `MAX_ISSUES_DRAWN` |
 | Rename | `RENAME_SEPARATOR`, `RENAME_PADDING`, `RENAME_SIDES`, `RENAME_TYPE_SUFFIXES` (plus `OBJECT_PREFIXES` / `DATABLOCK_PREFIXES` for *By Type* prefixes) |
-| Shot Viewer | `SHOT_VIEWER_RIG_GROUPS`, `SHOT_NAME_FORMAT`, `SHOT_NUMBER_STEP`, `SHOT_FRAME_START`, `SHOT_DEFAULT_DURATION`, `SEQUENCE_NAME_FORMAT`, `SHOT_CAMERA_NAME_FORMAT` |
+| Shot Viewer | `SHOT_VIEWER_RIG_GROUPS`, `SHOT_NAME_FORMAT`, `SHOT_NUMBER_STEP`, `SHOT_FRAME_START`, `SHOT_DEFAULT_DURATION`, `SEQUENCE_NAME_FORMAT`, `SHOT_CAMERA_NAME_FORMAT`, `SHOT_CAMERA_RIG_NAME_FORMAT`, `SHOT_CAMERA_RIG_MODES` |
 
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