feat(commands): add /commit command for conventional commits

Add streamlined commit workflow that analyzes staged changes and
generates conventional commit messages (feat:, fix:, etc.) with
user approval before committing.

Closes #18

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

commands/commit.md

@@ -0,0 +1,86 @@
+---
+description: Create a commit with an auto-generated conventional commit message. Analyzes staged changes and proposes a message for approval.
+argument-hint:
+---
+
+# Commit Changes
+
+## Process
+
+1. **Check for staged changes**:
+   ```bash
+   git diff --staged --stat
+   ```
+
+   If no staged changes, inform the user and suggest staging files first:
+   - Show unstaged changes with `git status`
+   - Ask if they want to stage all changes (`git add -A`) or specific files
+
+2. **Analyze staged changes**:
+   ```bash
+   git diff --staged
+   ```
+
+   Examine the diff to understand:
+   - What files were changed, added, or deleted
+   - The nature of the changes (new feature, bug fix, refactor, docs, etc.)
+   - Key details worth mentioning
+
+3. **Generate commit message**:
+
+   Create a conventional commit message following this format:
+   ```
+   <type>(<scope>): <description>
+
+   [optional body with more details]
+
+   Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+   ```
+
+   **Types:**
+   - `feat`: New feature or capability
+   - `fix`: Bug fix
+   - `refactor`: Code restructuring without behavior change
+   - `docs`: Documentation changes
+   - `style`: Formatting, whitespace (no code change)
+   - `test`: Adding or updating tests
+   - `chore`: Maintenance tasks, dependencies, config
+
+   **Scope:** The component or area affected (optional, use when helpful)
+
+   **Description:**
+   - Imperative mood ("add" not "added")
+   - Lowercase first letter
+   - No period at the end
+   - Focus on the "why" when the "what" is obvious
+
+4. **Present message for approval**:
+
+   Show the proposed message and ask the user to:
+   - **Approve**: Use the message as-is
+   - **Edit**: Let them modify the message
+   - **Regenerate**: Create a new message with different focus
+
+5. **Create the commit**:
+
+   Once approved, execute:
+   ```bash
+   git commit -m "$(cat <<'EOF'
+   <approved message>
+   EOF
+   )"
+   ```
+
+6. **Confirm success**:
+
+   Show the commit result and suggest next steps:
+   - Push to remote: `git push`
+   - Continue working and commit more changes
+
+## Guidelines
+
+- Only commits what's staged (respects partial staging)
+- Never auto-commits without user approval
+- Keep descriptions concise (50 chars or less for first line)
+- Include body for non-obvious changes
+- Always include Co-Authored-By attribution