refactor: standardize shell scripts with .sh extension (#54)

## Summary
This PR standardizes our shell script naming convention by adding the
`.sh` extension to all script files in the bin directory and updating
the corresponding references in the justfile.

## Key Accomplishments
- **Improved Script Identification**: All shell scripts now have
explicit `.sh` extensions, making them immediately recognizable as shell
scripts
- **Enhanced Developer Experience**: Scripts are now easier to identify
and work with in IDEs and text editors that rely on file extensions for
syntax highlighting and tooling
- **Consistent Naming Convention**: Establishes a clear standard for
future shell script additions to the project
- **Updated Build Configuration**: All script references in the justfile
have been updated to reflect the new naming convention

## Files Affected
- Renamed 4 shell scripts to include `.sh` extension
- Updated justfile to reference the renamed scripts

## Breaking Changes
⚠️ **Potential Impact**: Any external tools, documentation, or
automation that directly references the old script names will need to be
updated to use the new `.sh` extensions.

## Testing Notes
- Verify that all just commands continue to function correctly
- Ensure script execution permissions are preserved after the rename
- Test that any CI/CD pipelines or external integrations still work as
expected

## Infrastructure Considerations
This change improves maintainability and follows common shell scripting
conventions. The explicit file extensions will help with tooling
integration and make the codebase more accessible to new contributors.

---
🤖 Generated with [Claude Code](https://claude.ai/code)

**Branch Info:**
- Source: `refactor/rename-shell-files`
- Target: `main`
- Type: feature

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

Author: jfrench9

bin/create-feature bin/create-feature.shbin/create-feature renamed to bin/create-feature.sh

@@ -3,7 +3,7 @@ set -e
 
 # Create feature branch script - local Git operations
 # Creates a new feature/bugfix/hotfix branch locally and pushes to remote
-# Usage: ./bin/create-feature [feature|bugfix|hotfix|chore|refactor] [branch-name] [base-branch] [update-deps]
+# Usage: ./bin/create-feature.sh [feature|bugfix|hotfix|chore|refactor] [branch-name] [base-branch] [update-deps]
 
 # Default values
 BRANCH_TYPE=${1:-feature}

bin/create-pr bin/create-pr.shbin/create-pr renamed to bin/create-pr.sh

@@ -3,7 +3,7 @@ set -e
 
 # Create release script using GitHub Actions
 # Creates a new release branch via GHA workflow and checks it out locally
-# Usage: ./bin/create-release [major|minor|patch]
+# Usage: ./bin/create-release.sh [major|minor|patch]
 
 # Default to patch if no argument provided
 VERSION_TYPE=${1:-patch}

bin/create-release bin/create-release.shbin/create-release renamed to bin/create-release.sh

@@ -45,23 +45,23 @@ typecheck:
 
 # Generate SDK from localhost API
 generate-sdk url="http://localhost:8000/openapi.json":
-    bin/generate-sdk {{url}}
+    bin/generate-sdk.sh {{url}}
 
 # Build python package locally (for testing)
 build-package:
     python -m build
 
 # Create a feature branch
 create-feature branch_type="feature" branch_name="" base_branch="main" update="yes":
-    bin/create-feature {{branch_type}} {{branch_name}} {{base_branch}} {{update}}
+    bin/create-feature.sh {{branch_type}} {{branch_name}} {{base_branch}} {{update}}
 
 # Version management
 create-release type="patch":
-    bin/create-release {{type}}
+    bin/create-release.sh {{type}}
 
 # Create PR
 create-pr target_branch="main" claude_review="true":
-    bin/create-pr {{target_branch}} {{claude_review}}
+    bin/create-pr.sh {{target_branch}} {{claude_review}}
 
 # Clean up development artifacts
 clean: