feat(#1001): AI agent harness — state machine, capability registry, constrained tool protocol (Copilot v2 slice 1)

README.md

@@ -318,7 +318,7 @@ Split View|Skeleton Animation Controls
 - **AI part segmentation & PartOps** — detect a character's parts (head/torso/arms/legs), then **split** into named submeshes, **explode** into separate scene nodes, **join** them back, or **solidify** thin-shell parts; GUI + `qtmesh segment --split-parts / --explode-parts` + MCP (`split_mesh_by_segments`, `explode_mesh_parts`, `join_mesh_parts`) — see [docs/PART_OPS.md](docs/PART_OPS.md)
 - **Scene management** — duplicate (Ctrl+D), group (Ctrl+G), snap, pivot modes
 - **Performance capture** — video/webcam → facial morph animation (ARKit blendshapes), head pose, and full-body skeletal capture onto humanoid rigs; live preview + record in the editor, `qtmesh mocap` on the CLI (`-DENABLE_MOCAP` builds)
-- **AI chat** — natural language scene editing via local LLMs
+- **AI agent** — describe a task in natural language; a local LLM plans it over the editor's tools, runs it step by step with structured observations and replanning, groups it into ONE undo step, and asks before deleting or overwriting (agent mode; the simple chat loop is one click away)
 - **MCP server** — 57+ tools for AI agents (Claude, Cursor, etc.), including HDR/IBL (`set_hdr_environment`, `set_tonemap`, …) and QtMesh Cloud (`cloud_*`)
 - **REST API** — opt-in HTTP interface for external automation (`--with-mcp --http-port 8080`). Bound to **localhost** by default; tools execute only via `POST /api/tools/<name>` (`GET /api/tools` lists them); set `QTMESH_HTTP_TOKEN` (or `--http-token-file <path>`; a secret on the command line is refused, since `ps` shows it to every local user) to require `Authorization: Bearer <token>` on every request, and `--http-bind 0.0.0.0` only when you mean to expose it
 

qml/AISettingsDialog.qml

@@ -23,6 +23,8 @@ Dialog {
     property color buttonTextColor: palette.buttonText
     property string pendingDeleteModelId: ""
     property string pendingDeleteModelName: ""
+    property string pendingDeleteLlmFile: ""
+    property string pendingDeleteLlmName: ""
 
     SystemPalette {
         id: palette
@@ -224,11 +226,25 @@ Dialog {
 
                         Item { Layout.preferredHeight: 8 }
 
-                        Text {
-                            text: "Recommended Models"
-                            font.pointSize: 12
-                            font.bold: true
-                            color: textColor
+                        RowLayout {
+                            Layout.fillWidth: true
+                            spacing: 10
+                            Text {
+                                Layout.fillWidth: true
+                                text: "Recommended Models"
+                                font.pointSize: 12
+                                font.bold: true
+                                color: textColor
+                            }
+                            Local.ThemedButton {
+                                text: "Remove All"
+                                enabled: !ModelDownloader.isDownloading && LLMManager.availableModels.length > 0
+                                onClicked: removeAllLlmModelsDialog.open()
+                            }
+                            Local.ThemedButton {
+                                text: "Open Folder"
+                                onClicked: Qt.openUrlExternally(LLMManager.modelsDirectoryUrl)
+                            }
                         }
 
                         ListView {
@@ -279,6 +295,19 @@ Dialog {
                                             color: modelData.isDownloaded ? "#4caf50" : Qt.darker(textColor, 1.5)
                                         }
                                     }
+
+                                    // Same affordance as the QtMeshEditor Models tab: free the disk
+                                    // space of a downloaded GGUF (unloads it first if it is active).
+                                    Local.ThemedButton {
+                                        text: "Delete"
+                                        visible: modelData.isDownloaded
+                                        enabled: !ModelDownloader.isDownloading
+                                        onClicked: {
+                                            aiSettingsDialog.pendingDeleteLlmFile = modelData.fileName
+                                            aiSettingsDialog.pendingDeleteLlmName = modelData.name
+                                            removeLlmModelDialog.open()
+                                        }
+                                    }
                                 }
                             }
 
@@ -993,6 +1022,38 @@ Dialog {
         }
     }
 
+    Dialog {
+        id: removeLlmModelDialog
+        title: "Delete Model File"
+        modal: true
+        anchors.centerIn: parent
+        standardButtons: Dialog.Yes | Dialog.No
+        onAccepted: LLMManager.deleteModelFile(aiSettingsDialog.pendingDeleteLlmFile)
+
+        Text {
+            width: 360
+            text: "Delete " + aiSettingsDialog.pendingDeleteLlmName + " (" + aiSettingsDialog.pendingDeleteLlmFile + ") from the models folder? It is unloaded first if it is the active model."
+            color: textColor
+            wrapMode: Text.WordWrap
+        }
+    }
+
+    Dialog {
+        id: removeAllLlmModelsDialog
+        title: "Remove All LLM Files"
+        modal: true
+        anchors.centerIn: parent
+        standardButtons: Dialog.Yes | Dialog.No
+        onAccepted: LLMManager.deleteAllModelFiles()
+
+        Text {
+            width: 360
+            text: "Remove every downloaded GGUF model (" + LLMManager.availableModels.length + " file(s)) from the models folder? The active model is unloaded first."
+            color: textColor
+            wrapMode: Text.WordWrap
+        }
+    }
+
     Dialog {
         id: removeQtMeshModelDialog
         title: "Delete Model Files"