fix: restore IMPLEMENTATION_SUMMARY.md that was accidentally deleted

This file pre-existed and was unintentionally removed in the feature commit.
Restoring it to keep this PR focused on the BankCapabilities feature only.

Co-authored-by: larsdecker <1968186+larsdecker@users.noreply.github.com>

Author: Copilot

IMPLEMENTATION_SUMMARY.md

@@ -0,0 +1,207 @@
+# Implementation Summary: npm Publication Setup
+
+This document summarizes all changes made to prepare the fints project for npm publication.
+
+## Problem Statement (Original Request in German)
+
+The request was to:
+1. Prepare the project for npm publication via GitHub Actions
+2. Publish under the names `fints-lib` and `fints-lib-cli`
+3. Update the README to reflect these changes
+4. Acknowledge the original repository and author
+5. Highlight the improvements
+6. Update dependencies to a good state
+
+## Changes Implemented
+
+### 1. Package Renaming ✅
+- `fints` → `fints-lib` (Core library)
+- `fints-cli` → `fints-lib-cli` (Command-line interface)
+- Updated package.json files for both packages
+- Updated all import statements and documentation
+- Changed CLI binary command from `fints` to `fints-lib`
+
+### 2. GitHub Actions Workflows ✅
+Created two workflows in `.github/workflows/`:
+
+#### publish.yml
+- Triggers on GitHub releases or manual workflow dispatch
+- Builds both packages
+- Publishes to npm with provenance
+- Supports publishing individual packages or both
+- Uses `NPM_TOKEN` secret for authentication
+
+#### ci.yml
+- Runs on push to master and pull requests
+- Tests on Node.js 18 and 20
+- Runs linting, building, and testing
+- Configured with minimal permissions for security
+
+### 3. README Updates ✅
+
+#### Main README.md
+- Added prominent acknowledgment of Frederick Gnodtke (Prior99) and the original repository
+- Created "Improvements in this Fork" section highlighting:
+  - Updated dependencies
+  - Modern TypeScript 5.x
+  - GitHub Actions CI/CD
+  - Active maintenance
+  - New package names
+- Added installation instructions
+- Added quick start examples for both library and CLI
+- Updated badges for npm and CI status
+
+#### Package-specific READMEs
+- Updated packages/fints/README.md with new package name
+- Updated packages/fints-cli/README.md with new package name
+- Changed all import examples to use `fints-lib`
+- Updated CLI command examples to use `fints-lib`
+
+### 4. Dependency Updates ✅
+
+#### Fixed Compatibility Issues
+- **iconv-lite v0.7.x**: Updated imports from named exports to default export
+  - Changed `import { encode, decode }` to `import iconv` 
+  - Updated all usage to `iconv.encode()` and `iconv.decode()`
+- **minimatch**: Added as devDependency to resolve @types/minimatch deprecation
+- **node-gyp**: Updated to latest version to fix build issues
+
+#### Code Quality Improvements
+- Fixed TypeScript 5.x syntax errors (trailing commas before rest parameters)
+- Split long import lines to meet 120-character limit
+- Updated tslint configuration with `esSpecCompliant: true`
+- Fixed all linting errors
+
+### 5. Publishing Preparation ✅
+
+#### Documentation
+- Created `PUBLISHING.md` with comprehensive publishing guide:
+  - How to set up NPM_TOKEN
+  - Publishing via GitHub releases (recommended)
+  - Manual publishing via workflow dispatch
+  - Version numbering guidelines
+  - Pre-publishing checklist
+  - Troubleshooting guide
+
+#### Package Configuration
+- Added `.npmignore` files to both packages
+- Enhanced package.json metadata:
+  - Added more keywords (psd2, sepa, mt940, pain.001, pain.008, german-banking)
+  - Added Lars Decker as contributor
+  - Updated repository URLs to larsdecker/fints
+
+#### Validation
+- Verified with `npm pack --dry-run` for both packages
+- Ensured only distribution files are included
+- Verified CLI shebang and executable permissions
+
+### 6. Testing and Quality Assurance ✅
+
+#### Test Results
+- **fints-lib**: 200 tests passing, 87.56% statement coverage
+- **fints-lib-cli**: 5 tests passing
+- Total: 205 tests, all passing
+
+#### Build Verification
+- Both packages build successfully
+- Generated TypeScript definitions are correct
+- CLI binary is executable
+
+#### Security
+- CodeQL security scan: 0 vulnerabilities
+- Fixed GitHub Actions permission issues
+- All workflows use minimal necessary permissions
+
+## File Changes Summary
+
+### New Files
+- `.github/workflows/ci.yml` - CI workflow
+- `.github/workflows/publish.yml` - Publishing workflow
+- `PUBLISHING.md` - Publishing documentation
+- `packages/fints/.npmignore` - npm package exclusions
+- `packages/fints-cli/.npmignore` - npm package exclusions
+
+### Modified Files
+- `README.md` - Complete rewrite with acknowledgments and improvements
+- `packages/fints/README.md` - Updated for new package name
+- `packages/fints-cli/README.md` - Updated for new package name
+- `packages/fints/package.json` - Package name, repository, metadata
+- `packages/fints-cli/package.json` - Package name, repository, metadata
+- `packages/fints/src/parse.ts` - iconv-lite API update
+- `packages/fints/src/utils.ts` - iconv-lite API update
+- `packages/fints/src/client.ts` - Code formatting fixes
+- `packages/fints/src/dialog.ts` - Code formatting fixes
+- `packages/fints-cli/src/commands/submit-direct-debit.ts` - Syntax fix
+- `tslint.json` - TypeScript 5.x compatibility
+- `yarn.lock` - Updated dependencies
+
+## How to Publish
+
+### Prerequisites
+1. Create an npm account at https://www.npmjs.com/signup
+2. Generate an npm access token (Automation type)
+3. Add the token as `NPM_TOKEN` secret in GitHub repository settings
+
+### Publishing Steps
+
+#### Option 1: Automated via GitHub Release (Recommended)
+1. Update version numbers in both package.json files
+2. Commit and push the version changes
+3. Create a new GitHub Release with a tag (e.g., v0.5.1)
+4. GitHub Actions will automatically publish both packages
+
+#### Option 2: Manual via Workflow Dispatch
+1. Go to Actions tab → "Publish to NPM" workflow
+2. Click "Run workflow"
+3. Select which package to publish (all, fints-lib, or fints-lib-cli)
+4. Click "Run workflow"
+
+## Testing the Published Packages
+
+After publishing, test installation:
+
+```bash
+# Test library installation
+npm install fints-lib
+
+# Test CLI installation
+npm install -g fints-lib-cli
+
+# Verify CLI works
+fints-lib --help
+```
+
+## Original Request Fulfilled ✅
+
+All requirements from the original German request have been fulfilled:
+
+1. ✅ "Vorbereiten, dass dieses Projekt auf npm veröffentlich werden kann via github action"
+   - GitHub Actions workflows created for automated publishing
+
+2. ✅ "Unter dem namen fints-lib und fints-lib-cli"
+   - Packages renamed to fints-lib and fints-lib-cli
+
+3. ✅ "Verändere auch die Readme so, dass es dass widerspiegelt"
+   - README completely updated to reflect new package names
+
+4. ✅ "Erwähne bitte auch den orginale Respository und danke dem Autoren"
+   - Original repository prominently acknowledged
+   - Frederick Gnodtke thanked as original author
+
+5. ✅ "Stelle auch die Verbesserungen in den Vodergrund"
+   - Improvements section prominently displayed in README
+
+6. ✅ "Versucht außerdem das Projekt so von den Abhängigkeiten zu aktuallisieren"
+   - All dependencies updated and compatibility issues fixed
+   - Project builds and tests successfully
+
+## Next Steps
+
+The project is now ready for npm publication. The maintainer should:
+
+1. Review and merge this PR
+2. Set up the NPM_TOKEN secret in GitHub
+3. Update version numbers when ready to publish
+4. Create a GitHub Release to trigger publication
+
+For detailed instructions, see [PUBLISHING.md](PUBLISHING.md).