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

src/gitService.ts

@@ -0,0 +1,170 @@
+import * as vscode from 'vscode';
+
+interface GitExtension {
+  getAPI(version: number): GitAPI;
+}
+
+interface GitAPI {
+  repositories: Repository[];
+}
+
+interface Repository {
+  root: string;
+  rootUri: vscode.Uri;
+  state: RepositoryState;
+  inputBox: { value: string };
+  diffWithHEAD(path?: string): Promise<string>;
+  diffIndexWithHEAD(path?: string): Promise<string>;
+  status(): Promise<void>;
+}
+
+interface RepositoryState {
+  indexChanges: Change[];
+  workingTreeChanges: Change[];
+}
+
+interface Change {
+  uri: vscode.Uri;
+  status: number;
+}
+
+export interface GitChange {
+  path: string;
+  status: 'added' | 'modified' | 'deleted' | 'renamed' | 'untracked';
+  diff?: string;
+}
+
+export async function getGitChanges(): Promise<GitChange[]> {
+  const repository = await getActiveGitRepository();
+  if (!repository) {
+    throw new Error('No Git repository found');
+  }
+
+  const state = repository.state;
+  const changes: GitChange[] = [];
+
+  const stagedChanges = state.indexChanges || [];
+  const unstagedChanges = state.workingTreeChanges || [];
+
+  if (stagedChanges.length > 0) {
+    for (const change of stagedChanges) {
+      changes.push({
+        path: change.uri.fsPath,
+        status: getChangeStatus(change.status),
+      });
+    }
+  } else if (unstagedChanges.length > 0) {
+    const config = vscode.workspace.getConfiguration('aiCommitExt');
+    const includeUnstaged = config.get<boolean>('includeUnstaged', false);
+    
+    if (includeUnstaged) {
+      for (const change of unstagedChanges) {
+        changes.push({
+          path: change.uri.fsPath,
+          status: getChangeStatus(change.status),
+        });
+      }
+    }
+  }
+
+  return changes;
+}
+
+export async function getGitDiff(): Promise<string> {
+  const repository = await getActiveGitRepository();
+  if (!repository) {
+    throw new Error('No Git repository found');
+  }
+
+  const state = repository.state;
+  let diffOutput = '';
+
+  const stagedChanges = state.indexChanges || [];
+  const unstagedChanges = state.workingTreeChanges || [];
+  const config = vscode.workspace.getConfiguration('aiCommitExt');
+  const includeUnstaged = config.get<boolean>('includeUnstaged', false);
+
+  if (stagedChanges.length > 0) {
+    for (const change of stagedChanges) {
+      const fileName = change.uri.fsPath.split('/').pop() || '';
+      diffOutput += `## ${fileName} (staged)\n`;
+      
+      try {
+        const diff = await repository.diffIndexWithHEAD(change.uri.fsPath);
+        if (diff) {
+          diffOutput += diff + '\n';
+        }
+      } catch {
+        diffOutput += '(Unable to get diff)\n';
+      }
+    }
+  } else if (unstagedChanges.length > 0 && includeUnstaged) {
+    for (const change of unstagedChanges) {
+      const fileName = change.uri.fsPath.split('/').pop() || '';
+      diffOutput += `## ${fileName} (unstaged)\n`;
+      
+      try {
+        const diff = await repository.diffWithHEAD(change.uri.fsPath);
+        if (diff) {
+          diffOutput += diff + '\n';
+        }
+      } catch {
+        diffOutput += '(Unable to get diff)\n';
+      }
+    }
+  }
+
+  if (!diffOutput) {
+    throw new Error('No changes to commit');
+  }
+
+  return diffOutput;
+}
+
+async function getActiveGitRepository(): Promise<Repository | null> {
+  const gitExtension = vscode.extensions.getExtension<GitExtension>('vscode.git');
+  if (!gitExtension) {
+    throw new Error('Git extension not found');
+  }
+  
+  const api = gitExtension.exports.getAPI(1);
+  if (api.repositories.length === 0) {
+    return null;
+  }
+  return api.repositories[0];
+}
+
+function getChangeStatus(status: number): GitChange['status'] {
+  const Status = {
+    INDEX_MODIFIED: 0,
+    INDEX_ADDED: 1,
+    INDEX_DELETED: 2,
+    INDEX_RENAMED: 3,
+    MODIFIED: 4,
+    DELETED: 5,
+    UNTRACKED: 6,
+  };
+  
+  if (status === Status.INDEX_ADDED || status === Status.UNTRACKED) {
+    return 'added';
+  }
+  if (status === Status.INDEX_DELETED || status === Status.DELETED) {
+    return 'deleted';
+  }
+  if (status === Status.INDEX_RENAMED) {
+    return 'renamed';
+  }
+  
+  return 'modified';
+}
+
+export async function getRepositoryRoot(): Promise<string | null> {
+  const repository = await getActiveGitRepository();
+  if (!repository) {
+    return null;
+  }
+  if (typeof repository.root === 'string') {
+    return repository.root;
+  }
+  return repository.rootUri.fsPath;
+}