feat: initial implementation of AI Commit Ext VS Code extension

- Add VS Code extension with OpenCode AI integration
- Generate Conventional Commit messages via SCM header button
- Include gitService for staged changes detection
- Include opencodeService for CLI invocation
- Add configuration options for model, includeUnstaged, notifications
- Add button disable during generation with progress indicator
- Add sparkle icon for the action button
- Include package.json, tsconfig, and basic project setup

package.json

@@ -0,0 +1,70 @@
+{
+  "name": "ai-commit-ext",
+  "displayName": "AI Commit Ext",
+  "description": "Generate commit messages using OpenCode AI",
+  "version": "0.0.1",
+  "publisher": "local",
+  "engines": {
+    "vscode": "^1.71.0"
+  },
+  "categories": [
+    "Other"
+  ],
+  "main": "./out/extension",
+  "activationEvents": [
+    "onCommand:aiCommitExt.generate"
+  ],
+  "scripts": {
+    "vscode:prepublish": "npm run compile",
+    "compile": "tsc -p ./",
+    "watch": "tsc -watch -p ./",
+    "test": "echo \"No tests yet\""
+  },
+  "devDependencies": {
+    "@types/node": "^25.5.2",
+    "@types/vscode": "^1.110.0",
+    "typescript": "^6.0.2",
+    "vscode": "^1.1.37"
+  },
+  "contributes": {
+    "configuration": {
+      "title": "AI Commit Ext",
+      "properties": {
+        "aiCommitExt.model": {
+          "type": "string",
+          "default": "",
+          "description": "OpenCode model to use (e.g. anthropic/claude-3-5-sonnet-20241022). Empty = default model."
+        },
+        "aiCommitExt.includeUnstaged": {
+          "type": "boolean",
+          "default": false,
+          "description": "Use unstaged changes if no staged changes exist"
+        },
+        "aiCommitExt.showNotification": {
+          "type": "boolean",
+          "default": true,
+          "description": "Show notification when commit message is generated"
+        }
+      }
+    },
+    "commands": [
+      {
+        "command": "aiCommitExt.generate",
+        "title": "Generate Commit Message",
+        "icon": "$(sparkle)",
+        "category": "AI Commit"
+      }
+    ],
+    "menus": {
+      "scm/title": [
+        {
+          "when": "scmProvider == git",
+          "command": "aiCommitExt.generate",
+          "group": "navigation",
+          "icon": "$(sparkle)",
+          "alt": "aiCommitExt.generate"
+        }
+      ]
+    }
+  }
+}